@article {JRN55386, title = {Genetic and productive background of Criollo cattle in Argentina, Mexico, Uruguay and the United States}, journal = {Journal of Arid Environments}, volume = {200}, year = {2022}, month = {2/1/2022}, pages = {104722}, abstract = {Cattle were first introduced to the Western Hemisphere in 1493 and by subsequent introductions from the Iberian Peninsula, providing the genetic background of the American Criollo cattle, with influences from Spanish, Portuguese and African breeds. Criollo{\textquoteright}s high adaptive capacity enabled them to spread and colonize a wide variety of environments. Their ancestry combined with local adaptations created the wide spectrum of American Criollo breeds that we see today, many currently at risk of extinction. We review the existing genetic and production data on the Argentinian, Mexican, Uruguayan and US Creole cattle that form the basis of the current and future research described in this special issue. In these countries, Criollo cattle became the basis of the livestock industry for the supply of meat, hides and animal work, until they were displaced by more specialized European and cebuine type cattle breeds at the end of the 19th century. Since then, Criollo herds remained mostly in marginal regions unsuitable for commercial breeds. Efforts by local producers and research institutions helped to preserve Criollo populations. Several studies have demonstrated that these animals can produce high quality meat and are more resistant to diseases, and emphasize their high fertility, calving ease, longevity and ability to adapt to harsh environments. Mexican Criollos have high genetic diversity but lack strong conservation programs. More detailed genetic characterization within each regional Criollo population is needed to establish appropriate conservation strategies. In US, Texas Longhorn cattle are closely related to Mexican Criollos, while Pineywoods show a stronger relationship with Iberian breeds. Variable levels of genetic diversity were found among all North American Criollos, probably due to crossbreeding. Criollos from Argentina and Uruguay showed clear divergence due to genetic isolation but clustered together, representing the southernmost expansion of bovine cattle in the Americas.}, keywords = {conservation, Creole cattle, Criollo, Genetic, genetics, Heritage cattle}, doi = {10.1016/j.jaridenv.2022.104722}, url = {files/bibliography/22-015.pdf}, author = {E. Armstrong and Felipe A. Rodr{\'\i}g Almeida and Matthew M. McIntosh and M. Poli and Andr{\'e}s F. Cibils and J. A. Mart{\'\i}nez-Quintana and M. F{\'e}lix-Portillo and Richard E. Estell} } @article {JRN55324, title = {Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non-forest ecosystems}, journal = {Remote Sensing in Ecology and Conservation}, year = {2021}, month = {7/7/2021}, abstract = {Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9\%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1{\textendash}10 ha-1. Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.}, keywords = {Canopy height model, drone, fine spatial resolution remote sensing, plant height, structure-from-motion photogrammetry, UAV}, doi = {10.1002/rse2.228}, url = {files/bibliography/21-035.pdf}, author = {Andrew M. Cunliffe and Karen Anderson and Fabio Boschetti and Richard E. Brazier and Hugh A. Graham and Isla H. Myers-Smith and Thomas Astor and Matthias M. Boer and Leonor G. Calvo and Patrick E. Clark and Michael D. Cramer and Miguel S. Encinas-Lara and Stephen M. Escarzaga and Maria Fern{\'a}ndez-Gim{\'e}nez and Adrian G. Fisher and Breahna M. Gillespie and Anne Griebel and Niall Hanan and Muhammad S. Hanggito and Stefan Haselberger and Caroline A. Havrilla and Phil Heilman and W Ji and Jason W. Karl and Mario Kirchhoff and Sabine Kraushaar and Mitchell B. Lyons and Irene Marzolff and Marguerite Mauritz and Cameron D. McIntire and Daniel Metzen and Luis A. M{\'e}ndez-Barroso and Simon C. Power and Ji{\v r}{\'\i} Pro{\v s}ek and Enoc Sanz-Ablanedo and Katherine J. Sauer and Damian Schulze-Br{\"u}ninghoff and Petra {\v S}{\'\i}mov{\'a} and Stephen Sitch and Julian L. Smit and Caitriana Steele and Susana Su{\'a}rez-Seoane and Sergio A. Vargas and Miguel L Villarreal and Fleur Visser and Michael Wachendorf and Hannes Wirnsberger and Robert Wojcikiewicz} } @article {JRN55335, title = {The genesis of the Jornada criollo cattle program}, journal = {Journal of Arid Environments}, volume = {193}, year = {2021}, month = {6/11/2021}, abstract = {Many rangelands in the southwestern United States have experienced increased shrub cover and lower and more variable forage resources during the past 100 years. Criollo cattle are descendants of cattle brought to the Americas by European explorers that spread throughout North and South America. These cattle were displaced in many areas as British breeds became popular, but isolated populations remained that had undergone natural selection for nearly 500 years. Scientists at the Jornada Experimental Range in Las Cruces, New Mexico introduced Raramuri criollo genetics from the Tarahumara region of Chihuahua, Mexico to the research herd about 15 years ago in an effort to capitalize on their ability to thrive in harsh landscapes of the Chihuahuan Desert. They hypothesized that this smaller framed animal might be more suited to extensive shrubby landscapes and exert a lower environmental footprint than cattle of European descent. Preliminary observations during the early years of this project suggested that behavioral characteristics of this biotype could potentially be used to improve utilization of extensive rangelands with restricted water distribution. Raramuri criollo generally traveled farther per day and farther from water than Angus x Hereford crossbreds typically raised on these rangelands. Approximately five years ago, the Jornada expanded this program by joining forces with scientists from New Mexico State University, Mexico, and South America. Several studies were initiated that encompassed aspects of behavior, distribution, habitat and ecological site use, maternal behavior, diet selection, heat tolerance, and performance of Raramuri criollo cattle. Many of the results from these collaborations are reported in this special issue.}, keywords = {beef cattle, criollo cattle, Heritage beef cattle}, doi = {10.1016/j.jaridenv.2021.104563}, url = {files/bibliography/21-047.pdf}, author = {Richard E. Estell} } @conference {JRN55297, title = {Grass-cast: an experimental grassland productivity forecast}, booktitle = {Society for Range Management Meeting Abstracts}, year = {2020}, abstract = {Every spring, ranchers face the same difficult challenge{\textemdash}trying to guess how much grass will be available for livestock to graze during the upcoming growing season. Since May 2018, an innovative Grassland Productivity Forecast or {\textquotedblleft}Grass-Cast{\textquotedblright} has been helping producers in the Great Plains reduce this economically important source of uncertainty. This experimental grassland forecast is the result of collaboration between the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS), Climate Hubs, and Natural Resources Conservation Service (NRCS); the National Drought Mitigation Center (NDMC); Colorado State University and the University of Arizona. Grass-Cast provides land managers with an indication of what productivity is likely to be in the upcoming growing season relative to their own county{\textquoteright}s history. Grass-Cast uses over 30 years of historical data on weather and vegetation growth{\textemdash}combined with remotely-sensed NDVI data and seasonal precipitation forecasts{\textemdash}to predict if rangelands in individual ~6 mile x 6 mile areas are likely to produce above-normal, near-normal, or below-normal amounts of vegetation. The program{\textquoteright}s accuracy improves as the growing season unfolds, so it should be consulted more than just once during the growing season. The maps are updated every two weeks to incorporate newly observed weather data and emerging trends in grazing conditions. This tool can help rangeland managers better anticipate drought and prepare for shortages in grazing resources while also providing a view of rangeland productivity in the broader region to help with larger-scale decision making, such as determining where grazing resources might be more plentiful if their own region is at risk from drought. Grass-Cast is currently available to producers in the Great Plains and the Southwest (NM and AZ) Regions of the U.S.}, author = {Kramer, Lauren and Emile H. Elias and Dannele E. Peck and William Parton and Hartman, Melannie and J. D. Derner and Smith, William and Fuchs, Brian} } @article {JRN54916, title = {The generation and redistribution of soil cations in high elevation catenas in the Fraser Experimental Forest, Colorado, U.S.}, journal = {Geoderma}, volume = {333:135-144}, year = {2019}, month = {01/2019}, abstract = {

Pedogenic processes imprint their signature on soils over the course of thousands to millions of years in most soil systems. Variation in soil forming processes {\textendash} such as parent material weathering, organic material additions, hydrologic processes, and atmospheric additions {\textendash} account for the distribution and sourcing of cations in ecosystems, and hence exert a strong influence on ecosystem productivity. Soil nutrient dynamics of cations also provide an indication of the dominant soil forming processes at work in a particular system. To gain insight into the generation and distribution of the soil cation pool in the Fraser Experimental Forest (FEF), we combined geochemical mass balance techniques and isotopic analyses of soil geochemical data to pedons across eight soil catenas in complex mountain terrain typical of the central Rocky Mountains. We found that mass gains in FEF soils are primarily attributable to pedogenic additions of Ca to the soil mantle via atmospheric dust, and specifically that soil catenas on the summit landscapes were most enriched in Ca. Our data also show that atmospheric deposition contributions (calculated using Sr isotope ratios) to soils is as high as 82\% ({\textpm} 3\% SD), and that this isotopic signature in A-horizons and subsurface soil horizons diverges along a soil catena, due to both vertical and lateral hydrologic redistribution processes. Our results suggest that long term soil development and associated chemical signatures at FEF are principally driven by the coupling of landscape scale cation supply processes, snow distribution, and snowmelt dynamics. Soil development models describing pedogenesis across catenas in montane ecosystems must pay special attention to atmospheric inputs and their redistribution. Any changes to these dynamics will affect productivity and soil/water chemistry in such ecosystems as investigated here.

}, doi = {10.1016/j.geoderma.2018.07.024}, url = {files/bibliography/19-001.pdf}, author = {Bergstrom, Robert and Borch, Thomas and Martin, Patrick and Melzer, Susan and Rhoades, Chuck and S. W. Salley and E. Kelly} } @article {JRN55006, title = {Generalized and specific state-and-transition models to guide management and restoration of Caldenal forests}, journal = {Rangeland Ecology and Management}, volume = {72}, year = {2019}, month = {03/2019}, pages = {230-236}, chapter = {230}, abstract = {

Management impacts and natural events can produce ecosystem state changes that are difficult to reverse. In such cases, a detailed understanding of drivers, thresholds, and feedback mechanisms are needed to design restoration interventions. The Caldenal ecoregion in central Argentina has undergone widespread state change, and restoration is urgently needed, but as yet there has been no knowledge synthesis to support restoration actions. In this paper, we provide evidence-based guidelines for ecological restoration of the Caldenal forest derived from a general to local conceptual understanding of ecosystemdynamics.Wedevelop a Caldenal forest state transition model based on a generalized fire-mediated savanna-woodland transitionmodel. The generalizedmodel depicts global similarities in fire-grass feedback loops as a primary factor controlling savanna to woodland transition (thicketization) in semiarid savannas around the world. An open forest is considered to be the reference state of the Caldenal that developed under a historical regime of frequent low-intensity fire. The introduction of large livestock herds in the region disrupted the positive fire-grass feedback loop and increased dispersal and recruitment of Prosopis caldenia, creating conditions for thicketization of the forest. Controlled, low-intensity fire can be used to build the resilience of an open forest state. Restoring open forest states from woodland states requires
a large-scale selective thinning and pruning operation. Long-term restoration requires breaking the positive livestock-thicketization-high-intensity fire feedback and reestablishing the positive grass-lowintensity fire feedback to ensure the persistence of a restored open forest state.

}, keywords = {constraint to restoration, fire-mediated feedback, resilience, thicketization}, doi = {doi.org/10.1016/j.rama.2018.11.002}, url = {files/bibliography/19-007.pdf}, author = {H. Raul Peinetti and Brandon T Bestelmeyer and Chirino, Claudia and A. Kin and Frank Buss, Maria Elisa} } @article {JRN55134, title = {Grass-Shrub competition in arid lands: An overlooked driver in grassland-shrubland state transition?}, journal = {Ecosystems}, volume = {22}, year = {2019}, month = {04/2019}, pages = {619-628}, chapter = {619}, abstract = {

Traditional models of state transition in arid lands emphasize changes in disturbance regimes and abiotic feedbacks that promote the degradation of grassland into shrubland, while biotic interactions like competition and facilitation are often overlooked. Here, we conducted an experiment to determine whether shrubs have a positive, neutral, or negative effect on grasses, and if these interactions may play a role in grassland-shrubland state transition. Prosopis glandulosa shrub neighbors within 5 m of Bouteloua eriopoda grass patches were left intact (controls) or killed with foliar herbicide, and metrics of grass performance were evaluated over 5 years. We saw no evidence of shrub facilitation of grasses. Instead, grass ANPP responded positively to shrub removal in all years, but more so in years with above-average rainfall. Grass allocation to vegetative reproduction and grass patch size also increased when shrub neighbors were removed. These results demonstrate that biotic interference by shrubs upon grasses reinforce and magnify grazing- and drought-induced abiotic feedbacks during grassland{\textendash}shrubland transitions. Shrub effects on grass should therefore be considered a key process in desert grassland state transitions.

}, keywords = {Bouteloua eriopoda, Chihuahuan Desert, competition, grassland, prosopis glandulosa, Scrublands, state transition, woody plant encroachment}, doi = {doi.org/10.1007/s10021-018-0290-9}, url = {files/bibliography/19-016.pdf}, author = {Nathan Pierce and Steven R. Archer and Brandon T Bestelmeyer and D. K. James} } @article {JRN55159, title = {Grazing reduces the temporal stability of temperate grasslands in northern China}, journal = {FLORA}, volume = {259}, year = {2019}, month = {09/17/2019}, abstract = {

Grazing activity can profoundly influence grassland plant community structure and ecosystem functions. However, our understanding of the effects of livestock grazing on ecological stability across different grassland types remains limited. Based on a 5-year investigation along a precipitation gradient (180mm in desert steppe, 282mm in typical steppe and 375mm in meadow steppe) in temperate grasslands of Inner Mongolia, we examined the responses of the temporal stability of plant community aboveground biomass to grazing intensity at three levels (light grazing, moderate grazing and heavy grazing). We found that grazing intensity at all levels reduced biomass temporal stability across all types of grasslands. Heavy grazing intensity reduced community biomass, species richness and species asynchrony. Structural equation modeling further revealed that grazing decreased community stability mainly by decreasing species asynchrony. In addition, community-level stability was driven by grass species stability in the meadow steppe, but it was affected by the stability of forb species in the desert steppe. These findings suggest that grazing practices may alter the stability properties of grassland plant communities, highlighting the importance of understanding changes in different plant functional groups for predicting community dynamics under grazing management.

}, keywords = {Community stability, Grazing intensity, Species asynchrony, species richness, Steppe}, doi = {10.1016/j.flora.2019.151450}, url = {files/bibliography/19-022.pdf}, author = {Qin, J. and Ren, H. and G. Han and J. Zhang and Dawn M. Browning and Walter Willms and Yang, D.} } @article {JRN54925, title = {The Grassland{\textendash}Shrubland Regime Shift in the Southwestern United States: Misconceptions and Their Implications for Management}, journal = {Bioscience}, volume = {68}, year = {2018}, month = {09/2018}, pages = {678-690}, chapter = {678}, abstract = {

Transitions from semiarid grassland to shrubland states are among the most widely recognized examples of regime shifts in terrestrial ecosystems. Nonetheless, the processes causing grassland{\textendash}shrubland transitions and their consequences are incompletely understood. We challenge several misconceptions about these transitions in desert grasslands, including that (a) they are currently controlled by local livestock grazing and drought events, (b) they represent severe land degradation, and (c) restoration of grassland states is impossible. Grassland{\textendash}shrubland transitions are the products of multiple drivers and feedback systems, both ecological and social, interacting at multiple scales of space and time. Grass recovery within shrubland states{\textemdash}with and without shrub removal{\textemdash}produces novel ecosystems that are dissimilar from historical grasslands but that provide important ecosystem services. Projected increases in climate variability are likely to promote the further displacement of perennial grasses by xerophytic shrubs. This article offers guidelines for managing grassland{\textendash}shrubland transitions in the face of changing biophysical and socioeconomic circumstances.

}, keywords = {long term data, novel ecosystems, restoration, social-ecological, state transition, threshold}, doi = {doi.org/10.1093/biosci/biy065}, url = {files/bibliography/18-016.pdf}, author = {Brandon T Bestelmeyer and Debra C. Peters and Steven R. Archer and Dawn M. Browning and Gregory S. Okin and Robert L. Schooley and Nicholas Webb} } @article {JRN55174, title = {Global citizen science for people}, journal = {Frontiers in Ecological Environment}, volume = {16}, year = {2018}, month = {11/2018}, pages = {491}, chapter = {491}, abstract = {

Polarized public discourse often seems to favor opinion over evidence, while threats of science funding cuts suggest that evidence may also become less available. It{\textquoteright}s easy to get discouraged. In the past two decades, references to {\textquotedblleft}globalization{\textquotedblright} were often met with similar concerns. We believe that this attitude is changing, due in part to a recognition of the benefits of globalized access to environmental knowledge.

The Ecological Society of America (ESA) has contributed to this transition. In 2006, it brought together a group of 500 participants in M{\'e}rida, Mexico, to consider the topic, {\textquotedblleft}Ecology in an Era of Globalization: Challenges and Opportunities for Environmental Scientists in the Americas{\textquotedblright} (see the resulting Frontiers{\textquoteright} Special Issue: https://bit.ly/2Qv1dhr). The participants were overwhelmingly from the generation that drove the explosive growth of global social networks as tools to access and share knowledge and information. Many of the discussions, both formal and informal, reflected a desire to focus on opportunities, including accelerating the globalization of scientific discovery and access to knowledge. These opportunities have expanded dramatically as nearly everyone in the developed world, and a rapidly increasing number globally, now carries a highly sophisticated, networked, electronic lab notebook (ie cell phone) with them {\textendash} a notebook that includes an embedded camera and a variety of other environmental sensors.

Scientists who recognize the potential power of millions of cell phone owners have focused primarily on data collection, with the goal of expanding the spatial and temporal scope of traditional science. We argue that this perspective is myopic at best. Benefits of engaging citizens in the entire scientific process, including interpretation, include more informed land-use and management decisions, and a greater understanding of the value of evidence-based decision making. Citizen-science apps could also foster a sense of global community, interdependence, and trust in science as awareness grows of the value of data, information, and knowledge contributed by citizens in other countries. Being part of a global community can also empower individuals and organizations to challenge assumptions about perceived trade-offs between consumption and production, as farmers and ranchers begin to collect and optionally share more data about their sustainable production systems. This should also accelerate innovation through the exchange of ideas, information, and inspiration.

One of the outcomes of the 2006 ESA conference was a call for the development of an {\textquotedblleft}Environmental Knowledge System{\textquotedblright} that would facilitate {\textquotedblleft}dynamic access to, and interpretation of, traditional and non-traditional knowledge sources{\textquotedblright} with the assumption that this system would be delivered through internet cafes. In 2007 the first iPhone was sold. In 2018 village land-use planners in Tanzania began determining the sustainable production potential of their land based on data they collect and interpret with the Land-Potential Knowledge System (LandPKS; https://landpotential.org) mobile app. The development of this app was a direct outcome of the conference. Like most citizen-science apps, LandPKS provides a simple interface for data collection. But it also increasingly offers opportunities for users to visualize, manipulate, and interpret their data and, in the future, will serve as a gateway to other open-source tools, such as FarmOS (https://youtu.be/zua1y-hBcGc).

One of the lessons learned during the development of LandPKS and related apps is that a high level of engagement requires focusing on the immediate individual benefits for the citizens conducting the science, such as providing a service, or supporting site-specific management decisions, and less on long-term collective benefits of large, geographically dispersed datasets. One successful example is eBird (https://ebird.org), which has generated an incredibly valuable dataset by providing a useful bird identification service to its users.

We need to continue supporting successful initiatives like eBird. But we also need to expand citizen science so participants can use the scientific process, and easily access actionable scientific knowledge to make better decisions. This shift in focus can create positive feedback loops with benefits for all stakeholders. Land users can receive information better tailored to their unique circumstances, while scientists can obtain higher quality data to improve their models and decision-support tools.

We challenge the ecological community to work to support farmers, ranchers, land-use planners, and other natural resource managers with open-source, value-neutral tools that allow them to easily collect, share, and interpret their own data, and to apply these interpretations to manage their lands to be both more productive and more sustainable.

We believe that citizen science should go far beyond citizens contributing to science: it should also inspire and enable people to engage in the scientific process, so as to interpret their environment, make better decisions, innovate, and connect with other people around the world.

}, doi = {https://doi.org/10.1002/fee.1716}, url = {bibliography/18-028.pdf}, author = {Jeffrey E. Herrick and Cox, Dorn and Lundgren, Britt and Nindi, Stephen} } @article {JRN54846, title = {Groundwater recharge in desert playas: current rates and future effects of climate change}, journal = {Environmental Research Letters}, volume = {13 014025}, year = {2018}, month = {01/2018}, pages = {10 pp.}, abstract = {

Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause up to a 300\% increase in annual groundwater recharge beneath playas. This increase will overshadow the effect of decreased precipitation amount that could cause up to a 50\% decrease in recharge beneath playas. These changes could have a significant impact on groundwater and carbon storage. These results are important given that groundwater resources in Southwestern USA continue to decline due to human consumption outpacing natural recharge of aquifers. Here, we report on groundwater recharge rates ranging from less than 1 mm to greater than 25 mm per year beneath desert playas. Playas located in larger and steeper catchments with finer-textured soils had the highest rates of recharge. Vegetation cover had no effect on recharge beneath playas.We modeled catchment runoff generation and found that the amount of runon a playa receives annually strongly correlated to the rate of groundwater recharge beneath that playa. Runon occurred during precipitation events larger than 20 mm and increased linearly with events above that threshold.

}, keywords = {climate change, desert playas, groundwater recharge, Jornada LTER, precipitation variability, runoff modeling, watershed ecology}, doi = {https://doi.org/10.1088/1748-9326/aa9eb6}, url = {/files/bibliography/18-001.pdf}, author = {Owen P. McKenna and O. E. Sala} } @proceedings {JRN54866, title = {Grassland-shrubland state transitions in arid rangelands: Competition matters}, volume = {January 28-February 2, 2018}, year = {2018}, month = {01/28/2018}, publisher = {Society for Range Management Meeting Proceedings}, address = {Sparks, Nevada}, abstract = {

Background: State transition from grassland to shrubland is synonymous with desertification in many arid rangeland systems. Traditional desertification models emphasize abiotic feedbacks that modify the physical environment in ways that promote shrub proliferation and impede grass survival. Inherent in this perspective is the assumption that biotic interactions between grasses and shrubs have little bearing on state transition dynamics. Furthermore, the extent to which density-dependent interactions among shrubs might determine the magnitude and pattern of their cover is unknown. We addressed these assumptions and knowledge gaps over 4 years using selective removal experiments. Shrub-on-Grass Interactions: Grass ANPP responded positively to shrub removal in all years, but more so in years with above-average rainfall and in plots with high shrub abundance. Grass allocation to vegetative reproduction and grass patch area also increased when shrub neighbors were removed. These results demonstrate that biotic interference by shrubs upon grasses can reinforce and magnify abiotic feedbacks during grassland{\textendash}shrubland transitions. Grass-on-Shrub Interactions: In years with above-average growing season precipitation, ANPP of small shrubs increased when grasses were removed, a result not evident in dry years or in larger shrubs. Grasses may therefore slow the rate at which shrubs attain a physical stature that can modify the physical environment in self-promoting ways. Shrub-Shrub Interactions: Intraspecific interactions between shrubs were not evident in any year, supporting the assumption that abiotic variables rather than competitive interactions constrain maximum shrub cover. Summary: Results from these field experiments provide insights on how shrub-grass interactions amplify or dampen the abiotic drivers of desertification, help explain how woody plants can continue to proliferate despite low or reduced livestock grazing pressure, and generate hypotheses that can help us refine experiments to address the mechanisms of belowground competition at play where grasses and shrubs co-occur in arid ecosystems.

}, author = {Nathan Pierce and Steven R. Archer and Brandon T Bestelmeyer} } @article {JRN54871, title = {Ground cover, erosion risk and production implications of targeted management practices in Australian mixed farming systems: lessons from the Grain and Graze program}, journal = {Agricultural Systems}, volume = {162}, year = {2018}, month = {02/2018}, pages = {123-135}, chapter = {123}, abstract = {

Maintaining the productive capacity of the agricultural soils of Australia{\textquoteright}s broadacre cropping zone requires careful management, given a highly variable climate and soils that are susceptible to degradation. Mixed croplivestock farming systems are the predominant land use across these regions and managers must operate farms for long-term sustainability as well as shorter-term profitability. Achieving profitable and sustainable businesses has required ongoing innovation and productivity gains, of which the integration of crop and livestock enterprises has been an important part. Production-soil erosion trade-offs associated with enterprise integration is critical information that has not been investigated to date at a whole-farm level. The objective of this study as to systematically evaluate management options developed in Grain and Graze (an integrated program of research, development and extension targeting mixed farms) to identify farm systems responses to soil erosion risks across seven regions spanning the mixed-farming area of Australia. To evaluate production-soil erosion trade-offs, we linked the APSIM soil water, soil nutrient cycling, annual crop and surface residue simulation models to the GRAZPLAN pasture and ruminant simulation models, using the AusFarm modelling software. Our results demonstrate that the management options tested in Grain and Graze support the principles of \ conservation agriculture and inform the sustainable intensification of mixed farming systems. Across the regions considered we found that: (1) Increasing pasture legume content and soil fertility can consistently benefit farm production and environmental indicators, (2) management interventions that target direct management of ground cover have the greatest potential to reduce soil erosion rates, (3) management during critical periods of naturally high soil erodibility and wind/water erosivity can substantially increase or decrease erosion risk; the timing of management interventions is therefore critical, and (4) grazing management to balance use of crop residues and pasture biomass is required to avoid developing hot spots of erosion and soil degradation.

}, doi = {10.1016/j.agsy.2018.02.001}, url = {files/bibliography/18-002.pdf}, author = {Dean Thomas and A. Moore and Bell, Lindsay and Nicholas Webb} } @article {JRN54629, title = {Global-change drivers of ecosystem functioning modulated by natural variability and saturating responses}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {503-511}, abstract = {

Humans are altering global environment at an unprecedented rate through changes in biodiversity, climate, nitrogen cycle, and land use. To address their effects on ecosystem functioning, experiments most frequently explore one driver at a time and control as many confounding factors as possible. Yet, which driver exerts the largest influence on ecosystem functioning and whether their relative importance changes among systems remain unclear. We analyzed experiments in the Patagonian steppe that evaluated the aboveground net primary production (ANPP) response to manipulated gradients of species richness, precipitation, temperature, nitrogen fertilization (N), and grazing intensity. We compared the effect on ANPP relative to ambient conditions considering intensity and direction of manipulations for each driver. The ranking of responses to drivers with comparable manipulation intensity was as follows: biodiversity\>grazing\>precipitation\>N. For a similar intensity of manipulation, the effect of biodiversity loss was 4.0, 3.6, and 1.5, times larger than N deposition, decreased precipitation, and increased grazing intensity. We interpreted our results considering two hypotheses. First, the response of ANPP to changes in precipitation and biodiversity is saturating, so we expected larger effects when the driver was reduced, relative to ambient conditions, than when it was increased. Experimental manipulations that reduced ambient levels had larger effects than those that increased them. Second, the sensitivity of ANPP to each driver is inversely related to the natural variability of the driver. In Patagonia, the ranking of natural variability of drivers is as follows: precipitation\>grazing\>temperature\>biodiversity\> N. So, in general, the ecosystem was most sensitive to drivers that varied the least. Comparable results from Cedar Creek (MN) support both hypotheses and suggest that sensitivity to drivers varies among ecosystem types. Given the importance of understanding ecosystem sensitivity to predict global-change impacts, it is necessary to design new experiments located in regions with contrasting natural variability and that include the full range of drivers.

}, keywords = {ANPP, biodiversity loss, climate change, ecosystem sensitivity, land-use change, nitrogen deposition}, doi = {10.1111/gcb.13441}, url = {files/bibliography/JRN00656.pdf}, author = {P. Flombaum and Laura Yahdjian and O. E. Sala} } @inbook {JRN54669, title = {Grassland Communities and Ecosystems}, booktitle = {Reference Module in Life Sciences}, year = {2017}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

This chapter describes global grassland communities and grassland ecosystems.

Grasslands represent one of the largest vegetation types on Earth and their existence is determined by water scarcity that in turn depends on precipitation and temperature. This vegetation type harbors a high diversity of plant species that mostly occurs at fine spatial scales because grasslands tend to be structurally simpler at coarser scales. Grassland species richness has strong and positive effects on primary production as a result of increasing niche complementarity with increasing diversity. Grasslands are among the most vulnerable ecosystems in the world because their diversity is threatened by human activity, mostly as a consequence of conversion into croplands.

}, keywords = {grassland communities, grassland ecosystems}, issn = {978-0-12-809633-8}, doi = {10.1016/B978-0-12-809633-8.02201-9}, author = {O. E. Sala and L. Vivanco and P. Flombaum} } @article {JRN54686, title = {Generalizing ecological site concepts of the Colorado Plateau for landscape-level applications}, journal = {Rangelands}, volume = {38:342-349}, year = {2016}, month = {12/2016}, abstract = {

The Colorado Plateau is an iconic landscape of the American West{\textemdash} containing dozens of national parks, monuments, historic sites, and several UNESCO World Heritage Sites{\textemdash} including some of the Nation{\textquoteright} s most recognizable landmarks, such as the Grand Canyon and the Arches National Park. The concentration of outdoor destinations has led to a rapid increase in recreational tourism on the Plateau{\textemdash} visitation to the Arches National Park has nearly doubled over the last 15 years. \ Energy development (mostly oil and gas) has also accelerated in recent years, with a threefold increase in drilling rates in Utah between 2000 and 2008. Agriculture has been an important activity in the region from the prehistoric ages to modern times, with irrigated agriculture carried out in locations with suitable soils and water and domestic livestock grazing (primarily cattle) occurring across the majority of the region. Management of these co-occurring land uses are complicated by forecasts of a more arid and variable climate in the southwestern United States.

}, doi = {10.1016/j.rala.2016.10.010}, url = {files/bibliography/16-036.pdf}, author = {Danielle Duni and Travis Nauman and J. Johansen and Green, Shane and M. Miller and Jebediah C. Williamson and Brandon T Bestelmeyer} } @article {JRN54628, title = {Grazing lands in Sub-Saharan Africa and their potential role in climate change mitigation: What we do and don{\textquoteright}t know}, journal = {Environmental Development}, volume = {19}, year = {2016}, month = {07/2016}, pages = {70-74}, abstract = {
Grazinglands cover much of sub-Saharan Africa. When well-managed, these lands provide a wide variety of ecosystem services, many of which are positively correlated with increase in soil carbon. Pastoralists and other land managers are currently rewarded primarily for the production of animal products. This paper reviews the current literature and related knowledge on carbon sequestration in sub-Saharan grazinglands as the basis for six sets of recommendations. 1. C sequestration for climate change mitigation should be treated as a co-benefit rather than the target of a project/activity. 2. \ Paying people to maintain C stocks by persisting with existing good practices is likely to be easier than introducing new practices to increase stocks, although problems of paying multiple smallholders would remain. 3. \ Projects should be developed with strong input from the communities living in the areas (bottom up) where the project is to occur so that they have a sense of ownership and are then more likely to cooperate in its implementation. 4. When resources are limited, the focus should be on areas where the co-benefits of C sequestration and livelihood improvement are highest and this may be in moderately rather than severely degraded areas. Interventions should consider net livelihoods of local populations as a key metric of success of programs that are aiming to improve rangeland health and C sequestration. 5. Weak evidence of the impact of rangeland management approaches in enhancing C sequestration in non-equilibrial (erratic and changing) systems makes it \ more difficult to detect management responses and therefore justify management actions. However, carefuly analysis is required since the long-term costs of neglecting these systems may be higher in some cases due to the difficulty of restoration where biophysical thresholds have been crossed. 6. From a purely biophysical C sequestration point of view, investment should be in areas where mineralization rates are low (cold, moist) or input rates are high (warm, wet). In areas where C sequestration rates are likely to be lower (arid, semi-arid) but cover extensive land areas, projects should include C sequestration as part of a package of multiple benefits in which practices that sequester C in grasslands enhance productivity, improve livelihoods, increase biodiversity and benefit multiple ecosystem services.\ 
}, doi = {http://dx.doi.org/10.1016/j.envdev.2016.06.001}, url = {files/bibliography/16-014.pdf}, author = {Milne, Elenor and Aynekulu, E. and Bationo, A. and Batjes, Niles H. and Boone, R. D. and R. Conant and J. Davis and Niall Hanan and Hoag, D. and Jeffrey E. Herrick and Knausenberger, W. and Neely, C. and Njoka, J. and Ngugi, M. and Parton, B. and Paustian, K. and Reid, R. and Said, M. and Shephers, K. and Swift, D. and Thornton, P. and S. Williams} } @conference {JRN54645, title = {Grassland-shrubland state transitions in arid lands: Competition matters}, booktitle = {Ecological Society of America}, year = {2016}, month = {08/2016}, publisher = {Ecological Society of America Abstracts}, organization = {Ecological Society of America Abstracts}, address = {Fort Lauderdale, FL}, abstract = {
Background/Question/Methods: State transition from grassland to shrubland is synonymous with desertification in many dryland systems. The classic desertification model emphasizes abiotic feedbacks that modify the physical environment in ways that promote shrub proliferation and impede grass survival. Inherent in this perspective is the assumption that biotic interactions between grasses and shrubs have little bearing on state transition dynamics. Furthermore, the importance of density-dependent interactions as determinants of shrub cover is unknown. We addressed these assumptions and knowledge gaps over 4 years using selective removal (SR) experiments. In SR1, shrubs (Prosopis glandulosa) were killed (foliar herbicide) or left intact (controls) and growth of grasses (Bouteloua eriopoda) was quantified. In SR2, productivity of shrubs whose local grass neighborhoods had been neutralized by herbicide or left intact was monitored. In SR3, ANPP of shrubs whose conspecific neighbors were intact or killed was quantified.
Results/Conclusions: Shrub-on-Grass Interactions: Grass ANPP responded positively to shrub removal in all years, but more so in years with above-average rainfall and in plots with high shrub abundance. Grass allocation to vegetative reproduction and grass patch area also increased when shrub neighbors were removed. These results demonstrate that biotic interference by shrubs upon grasses reinforce and magnify abiotic feedbacks during grassland{\textendash}shrubland transitions. Grass-on-Shrub Interactions: In years with above-average growing season precipitation, ANPP of small shrubs increased when grasses were removed, a result not evident in dry years or in larger shrubs. Grasses may therefore slow the rate at which shrubs attain a physical stature that can modify the physical environment in self-promoting ways. Shrub-Shrub Interactions: Intraspecific interactions between shrubs were not evident in any year, supporting the assumption that abiotic variables rather than competitive interactions constrain maximum shrub cover. This research provides insights on how shrub-grass interactions amplify or dampen the abiotic drivers of desertification, helps explain how woody plants can continue to proliferate despite low or reduced livestock grazing pressure, and generates hypotheses that can help us refine experiments to address the mechanisms of belowground competition at play where grasses and shrubs co-occur in arid ecosystems.
}, author = {Pierce, K. and Steven R. Archer and Brandon T Bestelmeyer} } @article {JRN54160, title = {Grazing impacts on the susceptibility of rangelands to wind erosion: the effects of stocking rate, stocking strategy and land condition}, journal = {Aeolian Research}, volume = {17}, year = {2015}, month = {03/2015}, pages = {89-99}, chapter = {89}, abstract = {

An estimated 110 Mt of dust is eroded by wind from the Australian land surface each year, most of which originates from the arid and semi-arid rangelands. Livestock production is thought to increase the susceptibility of the rangelands to wind erosion by reducing vegetation cover and modifying surface soil stability. However, research is yet to quantify the impacts of grazing land management on the erodibility of the Australian rangelands, or determine how these impacts vary among land types and over time. We present a simulation analysis that links a pasture growth and animal production model (GRASP) to the Australian Land Erodibility Model (AUSLEM) to evaluate the impacts of stocking rate, stocking strategy and land condition on the erodibility of four land types in western Queensland, Australia. Our results show that declining land condition, over stocking, and using inflexible stocking strategies have potential to increase land erodibility and amplify accelerated soil erosion. However, land erodibility responses to grazing are complex and influenced by land type sensitivities to different grazing strategies and local climate characteristics. Our simulations show that land types which are more resilient to livestock grazing tend to be least susceptible to accelerated wind erosion. Increases in land erodibility are found to occur most often during climatic transitions when vegetation cover is most sensitive to grazing pressure. However, grazing effects are limited during extreme wet and dry periods when the influence of climate on vegetation cover is strongest. Our research provides the opportunity to estimate the effects of different land management practices across a range of land types, and provides a better understanding of the mechanisms of accelerated erosion resulting from pastoral activities. The approach could help further assessment of land erodibility at a broader scale notably if combined with wind erosion models.

}, keywords = {aeolian, dust, land degradation, rangeland management, soil erodibility, stocking rates}, doi = {10.1016/j.aeolia.2014.12.005}, url = {/files/bibliography/15-009.pdf}, author = {Aubault, Helene and Nicholas Webb and Craig Strong and Grant McTainish and John Leys and Scanlan, Joe C.} } @conference {JRN54423, title = {Geography as destiny? Social and ecological resilience in rangelands of the American southwest}, booktitle = {100th Annual Meeting, Ecological Society of America}, year = {2015}, month = {08/2015}, publisher = {ESA}, organization = {ESA}, address = {Baltimore, MD}, abstract = {

Background/Question/Methods:\  Social-ecological systems perspectives focus on the reciprocal relationships between human and natural ecosystem elements and how these interactions determine human well-being, ecological state change, and land use change. In the arid southwestern US, which is dominated by ranching, a deeper understanding of social-ecological relationships is critical because land use change is accelerating. Productive cattle ranches, for example, can remain within family ownership for generations, whereas limited ecological potential, ecological degradation, and the {\textquotedblleft}impermanence syndrome{\textquotedblright} can lead to repeated sales of other ranches. We asked whether we could predict expressions of social resilience (intrafamilial transfer of ownership vs. repeated ranch turnover to new owners) as a function of biophysical and geographic variables. In other words, are some ranches prone to failure? We studied an area dominated by federal public land (Bureau of Land Management grazing allotments) in southwestern New Mexico, USA. We examined the relationships of 1) frequency of ranch turnover and 2) intrafamilial transfer with variables related to 3) ecological resilience (soils, climate, departure from reference state) and 4) factors that may contribute to the perception of ranch impermanence (grazing allotment size and distance to the US-Mexico border and major cities). The dataset included 432 grazing allotments examined over a 70 year period.
Results/Conclusions: Our analysis supported the hypothesis that ranch ownership dynamics were related to ecological potential, ecological state, and ranch impermanence factors. The frequency of ranch turnover was positively related to the dominance of low-resilience (sandy) soils and degraded ecological states and negatively related to mean annual precipitation, distance from the US-Mexico border, and distance to major cities. Ranch turnover was positively related to grazing allotment size, perhaps because the largest allotments were established in the poorest soils under the Taylor Grazing Act (1934). In contrast, intrafamilial transfers were positively related to mean annual precipitation and distance from cities but negatively related to allotment size and the dominance of sandy soils. Thus, geographic position within the study area appears to be an important determinant of past land ownership dynamics. Future land use changes, including urban expansion, energy development, and establishment of conservation areas might also be predicted by ecological and impermanence factors.\  Abstract $\#$ LNG 1-8.

}, author = {Brandon T Bestelmeyer and R. K. Skaggs and Dawn M. Browning and Jebediah C. Williamson and Wojan, Chris} } @article {49850, title = {The global land-potential knowledge system (LandPKS): Supporting evidence-based, site-specific land use and management through cloud computing, mobile applications, and crowdsourcing}, journal = {Journal of Soil and Water Conservation}, volume = {68}, year = {2013}, month = {01/2013}, pages = {5A-12A}, chapter = {5A}, abstract = {

Agricultural production must increase significantly to meet the needs of a growing global population with increasing per capita consumption of food, fiber, building materials, and fuel. Consumption already exceeds net primary production in many parts of the world.\  In addition to reducing consumption, there are two options to meet these needs: production intensification and land conversion.\  The largest gains achievable through agricultural intensification will likely occur on lands with the largest unrealized production potential, or yield gap. These lands have high potential production and low current production. Similarly, the highest returns on investments to be gained by land conversion should occur on lands with the highest potential production, assuming similar infrastructure, per acre conversion costs, and other market conditions.\  This paper describes how a new cloud-based Land-Potential Knowledge System (LandPKS; www.landpotential. org) will allow land potential to be defined explicitly and dynamically for unique and constantly changing soil and climate conditions and to be updated based on new evidence about the success or failure of new management systems on different soils. The knowledge engine (figure 2), together with simple applications for mobile phones, will also facilitate more rapid and complete integration and dissemination of local and scientific knowledge about sustainable land management.

}, doi = {10.2489/jswc.68.1.5A }, url = {/files/bibliography/13-010.pdf}, author = {Jeffrey E. Herrick and K.C. Urama and Jason W. Karl and Boos, John and Mari-Vaughn V. Johnson and Keith Shepherd and Hempel, Jon and Brandon T Bestelmeyer and J. Davis and Guerra, Jose Larson and Kosnik, Chris and D.W. Kimiti and Ekai, Abraham L. and Muller, Kit and Norfleet, L.M. and Ozor, Nicholas and Reinsch, Thomas and J. Sarukhan and West, L.T.} } @article {JRN53967, title = {Geographic searching for ecological studies: A new frontier}, journal = {Trends in Ecology and Evolution}, volume = {28}, year = {2013}, month = {07/2013}, pages = {383-384}, type = {Review Article}, chapter = {383}, abstract = {

Important ecological knowledge contained in published literature is often overlooked by researchers, resource managers, and policymakers in part because most literature search tools are thematically focused and do not explicitly consider the geographic location of the research. Searching for ecological literature thematically and geographically would improve the ease of accessibility of potentially relevant research findings that could promote syntheses and meta-analyses, provide mechanistic understanding to environmental patterns, facilitate evaluations of bias in ecological knowledge, and limit redundancy in conducting new studies. New tools are beginning to enable geographic literature searching. For example, JournalMap (http://www.journalmap.org) is a simple geographic search engine for ecological literature based on study area descriptions. The online data repository Pangaea (http://www.pangaea.de) effectively maps journal articles by the locations of their data. The GLOBE project (http://globe.umbc.edu) supports searching for, and synthesis of, user-contributed georeferenced studies for land-change science. Additionally, several journals published by Elsevier offer the ability to include supplemental geographic data and interactive maps. All these efforts, however, suffer from the same shortcomings: they do not contain enough content to realize the potential of geographic literature searching, contributions are either voluntary or limited to specific groups, and most importantly, these efforts operate independently of each other. Consequently, the lack of accessible and searchable georeferenced content is currently limiting the potential of geographic literature searching. Achieving a meaningful spatial representation of ecological knowledge will require changing how and what information is published in the future, as well as confronting the challenge of georeferencing past studies. In the short term, two simple behaviors are imperative: (i) authors should take the initiative to include geographic coordinates and descriptive study area information in their study area descriptions; and (ii) journal editorial boards and publishers should begin discussions on how broad-scale geographic searching can become standard practice in scientific knowledge discovery.

}, doi = {10.1016/j.tree.2013.05.001}, url = {/files/bibliography/13-039.pdf}, author = {Jason W. Karl and Jeffrey K. Gillan and Jeffrey E. Herrick} } @article {JRN54555, title = {GPS/GIS technology in range cattle management}, journal = {Journal of Animal Science}, volume = {90, supple 3/J . }, year = {2012}, month = {07/2012}, chapter = {p. 426}, abstract = {Animal dominated landscapes are dynamic and not fully understood. Electronics were first employed in the mid-1970{\textquoteright}s to monitor free-ranging cattle behavior and its impact on forage utilization. By the mid-90{\textquoteright}s satellite positioning systems were being used to monitor wildlife and had all but removed human observation from animal tracking. However, not until the end of the 90{\textquoteright}s did animal born satellite receiver{\textquoteright}s catapult range cattle management into the world of microchip technology. This advent eliminated some challenges associated with terrestrial based systems but added others not the least of which has been how best to provide sustained power to animal born electronics. This question caused a conundrum for researchers deciding how to balance data collection rates with battery power drain since satellite based systems have the potential to collect data in fractions of a second. To assist in interpreting the vast reservoirs of time-stamped positional data available, researchers began looking to biotic and abiotic information in the vicinity of the animal{\textquoteright}s geographical location to help explain the animal{\textquoteright}s behavior. Enter the Geographic Information System (GIS) with its origins in the late 50{\textquoteright}s and 60{\textquoteright}s. It provides hardware and software capable of capturing, storing, retrieving, manipulating, analyzing, and displaying geographically referenced data. By combining GIS and Global Positioning System (GPS) satellite data researchers were given a robust way to accurately associate possible cause and affect relationships. Because of the complexity associated with electronically obtained data, it is mandatory that multifaceted teams be established from the onset not only to keep electronics operational but to optimize the design, gathering, summarization, analyses, interpretation and application of data. Though electronics have replaced the drudgery and incompleteness of manual data gathering, electronics should never be used in an attempt to replace the art of human observation and discernment that ultimately provides the interpretation and application of field based management.}, author = {D.M. Anderson} } @article {49873, title = {Grand challenges for resilience-based management of rangelands}, journal = {Rangeland Ecology and Management}, volume = {65}, year = {2012}, month = {11/2012}, pages = {654-663}, chapter = {654}, abstract = {

The social and ecological contexts for rangeland management are changing rapidly, prompting a reevaluation of science, management, and the linkages between them. Here, we argue that the recent transformation from a steady state to an ecosystem management model has served the rangeland profession well, but that further transformation to resilience-based management is required to ensure that rangeland services will continue to benefit society in an era of rapid change. Resilience-based management emphasizes collaborative management and social learning to guide adaptation and transformation in social-ecological systems. The objectives of this forum are to: 1) justify the need for adopting resilience-based management, 2) identify the challenges that will be encountered in its development and implementation, and 3) highlight approaches to overcoming these challenges. Five categories of challenges confronting the adoption of resilience-based management, based upon the insights of 55 of rangeland researchers that have contributed to this special issue, were identified as: a) development of knowledge systems to support resilience-based management, b) improvement of ecological models supporting science and management, c) protocols to assess and manage tradeoffs among ecosystem services, d) use of social-ecological system perspectives to achieve greater stakeholder participation, and e) reorganization of institutions to support resilience-based management. It has become clear that greater scientific knowledge by itself is insufficient to promote resilience-based management in rangelands. Resolving the challenges presented here will require the creation of stronger partnerships between ecosystem managers, science organizations, management agencies, and policymakers at local, regional, and national scales. The creation of social learning institutions tied to evolving knowledge systems is our best hope to guide adaptation and transformation in rangelands in the coming century.

}, keywords = {adaptive management, ecosystem services, knowledge systems, postmodern science, social-ecological systems, transformation}, doi = {10.2111/REM-D-12-00072.1}, url = {/files/bibliography/12-032.pdf}, author = {Brandon T Bestelmeyer and D.D. Briske} } @article {49883, title = {Generation of ensemble streamflow forecasts using an enhanced version of the snowmelt runoff model}, journal = {Journal of the American Water Resources Association}, volume = {48}, year = {2012}, month = {08/2012}, pages = {643-655}, chapter = {643}, abstract = {As water demand increases in the western United States, so does the need for accurate streamflow forecasts. We describe a method for generating ensemble streamflow forecasts (1-15 days) using an enhanced version of the snowmelt runoff model (SRM). Forecasts are produced for three snowmelt-dominated basins in Idaho. Model inputs are derived from meteorological forecasts, snow cover imagery, and surface observations from Snowpack Telemetry stations. The model performed well at lead times up to 7 days, but has significant predictability out to 15 days. The timing of peak flow and the streamflow volume are captured well by the model, but the peak-flow value is typically low. The model performance was assessed by computing the coefficient of determination (R2), percentage of volume difference (Dv\%), and a skill score that quantifies the usefulness of the forecasts relative to climatology. The average R2 value for the mean ensemble is \>0.8 for all three basins for lead times up to seven days. The Dv\% is fairly unbiased (within \±10\%) out to seven days in two of the basins, but the model underpredicts Dv\% in the third. The average skill scores for all basins are \>0.6 for lead times up to seven days, indicating that the ensemble model outperforms climatology. These results validate the usefulness of the ensemble forecasting approach for basins of this type, suggesting that the ensemble version of SRM might be applied successfully to other basins in the Intermountain West.}, keywords = {ensemble streamflow forecasting, quantitative modeling, snow hydrology, surface water hydrology, water supply}, doi = {10.1111/j.1752-1688.2012.00642.x}, url = {/files/bibliography/12-023.pdf}, author = {Harshburger, Brain D. and Walden, Von P. and K. S. Humes and Moore, Brandon C. and Blandford, Troy and A. Rango} } @inbook {49897, title = {Grassland simulation models: A synthesis of current models and future challenges}, booktitle = {Handbook of Ecological Models Used in Ecosystem and Environmental Management}, year = {2012}, pages = {175-201}, publisher = {CRC Pess}, organization = {CRC Pess}, chapter = {7}, address = {Baco Raton, FL}, abstract = {

This chapter synthesizes the different kinds of simulation models commonly used to address questions about controls on dynamics of perennial grasslands. Five major classes of models are described using specific models as examples: (1) demographic, (2) physiological, (3) physical, (4) biogeochemistry, and (5) dynamic global vegetation. Each class of model is described relative to the types of questions that can be addressed, and then its advantages and limitations are stated. Recommendations on which model to select for different kinds of questions are given as well as future challenges in grassland modeling are described. The chapter contains five tables, one for each model class, that provide detailed information on input parameters, spatial and temporal resolution, and response variables for specific models that will aide readers in selecting models for use in different situations. In addition, a comprehensive literature cited includes many of the more commonly used and published models for grasslands.

}, isbn = {978-1-4398-1812-1}, url = {/files/bibliography/12-004.pdf}, author = {Debra C. Peters} } @article {49923, title = {Geomorphology of the Chihuahuan Desert based on potential dust emissions}, journal = {Journal of Maps}, year = {2011}, pages = {249-259}, abstract = {

The Chihuahuan Desert of central northern Mexico and southern Arizona, New Mexico and Texas, USA, is a regionally significant dust {\textquoteleft}hot-spot{\textquoteright} in North America. Typical of other such hot-spots, this desert consists of a mosaic of geomorphological settings, each of which has a varying propensity for dust emission. Recently, a classification system of dust emission potential based on surface geomorphic characteristics that establishes a common framework for describing the land surface has been proposed. The classification is readily applicable to different dust source regions and designed to facilitate comparison of the relative potential dust contributions and emissivity of varying geomorphological environments in such regions.

The map here (1:3,500,000) was compiled by applying the new classification to a base map of polygons from existing soil and landform maps that were produced by national government agencies. Within the study area, 11 of the 17 possible geomorphic classes were present, the most extensive being unarmoured, unincised high relief alluvial surfaces, which covered 43\% of the area.

As an example of how empirical dust source point data can be used with the classification, the satellite observed origins of dust plumes for 26 major wind erosion events from 2001 to 2009 were overlain on the map. Despite a total area of only 4\%, ephemeral lakes were the source of 48\% of the observed plumes. This map and the relationships derived from it provide the basis for developing equivalent maps in other dusty regions, and mark a step toward improving the representation and documentation of the strength of dust sources in numerical mineral aerosol models.

}, keywords = {Chihuahuan Desert, dust emissions, ephemeral lakes, geomorphology, playas}, doi = {10.4113/jom.2011.1178}, url = {files/bibliography/JRN00566.pdf}, author = {Matthew C. Baddock and Thomas E. Gill and Joanna E. Bullard and Acosta, Dominguez and Rivera Rivera, Nancy I.} } @conference {JRN54586, title = {Grassland, shrubland and savanna stewardship: where do we go from here?}, booktitle = {96th Ecological Society of America Annual Meeting}, year = {2011}, month = {08/2011}, publisher = {Ecological Society of America}, organization = {Ecological Society of America}, address = {Austin, Texas}, abstract = {Scientific efforts to understand grasslands, shrublands and savannas and thereby develop sustainable management practices are roughly 100 years old. What have we learned in that time? Several assumptions made by scientists and policymakers early in the 20th century have proved mistaken, resulting in persistent degradation and many cases of unintended negative consequences. In particular, the belief that rangelands were only useful for livestock production no longer holds, and Clementsian ideas of succession and linear relations across scales of space and time have had to be replaced in light of empirical and theoretical advances in rangeland ecology.Successful stewardship in the 21st century will require policy revisions that address changing socio-economic conditions on rangelands in the US and abroad. Rapid land-use change{\textemdash}from livestock production to agriculture, urban development, and industry{\textemdash}requires policies that prevent fragmentation and preserve management options such as fire restoration. The discipline of rangeland ecology should partner with ranchers and pastoralists to study management effects at large spatial and long temporal scales, and to identify the times and places where opportunistic management practices can be implemented most effectively.}, author = {Brandon T Bestelmeyer and N. F. Sayre} } @inbook {49979, title = {Globalization: Ecological consequences of global-scale connectivity in people, resources, and information}, booktitle = {The Systemic Dimension of Globalization}, year = {2011}, pages = {211-232}, publisher = {InTech}, organization = {InTech}, chapter = {11}, abstract = {Globalization is a phenomenon affecting all facets of the Earth System. Within the context of ecological systems, it is becoming increasingly apparent that global connectivity among terrestrial systems, the atmosphere, and oceans is driving many ecological dynamics at finer scales and pushing thresholds of change. In addition, fine-scale ecological dynamics can propagate spatially to influence broad spatial extents with feedbacks to global drivers. Because global change drivers and ecosystem dynamics are changing nonlinearly through time for many locations, it is critical that connections across different aspects of the Earth System be examined to improve both understanding and prediction of future dynamics. Here, three classes of connectivity events are described that emerge from a common, integrated framework. Each class has different characteristics that connect ecological systems at fine to broad scales. Examples are provided to illustrate how various global change drivers can influence and interact with heterogeneity in land surface properties of vegetation and soil pattern to either synchronize, attenuate or amplify impacts of drivers on ecological systems. Approaches are also described to quantifying global change impacts and ecological responses when locations are connected spatially.}, isbn = {978-953-307-384-2}, url = {/files/bibliography/11-019.pdf}, author = {Debra C. Peters} } @inbook {49991, title = {Grassland ecosystems}, booktitle = {Encyclopedia of Biodiversity}, year = {2011}, publisher = {Elsevier}, organization = {Elsevier}, keywords = {biodiversity, grassland ecosystems}, author = {O. E. Sala and L. Vivanco and P. Flombaum} } @conference {50009, title = {Grassland restoration following mesquite invasion in the northern Chihuahuan Desert: Persistence, patience, and perspectives from the past and present}, booktitle = {Society for Range Management}, volume = {63rd Society for Range Management}, year = {2010}, pages = {Sym-22}, address = {Denver, CO}, abstract = {The widespread invasion of grasslands by woody plants in the northern Chihuahuan Desert over the past 100-150 years is well-documented, and has stimulated a large body of research about the mechanisms driving this conversion, as well as approaches to grassland restoration. Progressive invasion and eventual domination by mesquite (Prosopis glandulosa Torr.) is often associated with dramatic redistribution of soils, loss of herbaceous cover, and severely reduced ecological function. Restoration in this region is problematic due to low soil moisture availability and the instability of mesquite-dominated communities, particularly on coarse sandy soils. Historical efforts to rehabilitate invaded sites initially focused on implementing individual control methods and reseeding to restore vegetation structure. Progressively, the focus of restoration research has incorporated integrated management approaches aimed at recovering both structure and function. We provide a brief review of historical approaches, lessons learned, and the results of recent research involving simultaneous manipulations of vegetation, soils, and the soil seedbank.}, keywords = {Chihuahuan Desert, ecological, restoration}, author = {Laurie Abbott and Jeffrey E. Herrick and Kendal Young} } @conference {JRN54462, title = {Geospatial methods and data analysis for assessing distribution of grazing livestock }, booktitle = {4th Grazing Livestock Nutrition Conference }, year = {2010}, month = {07/2010}, address = {Estes Park, CO}, abstract = {

Free-ranging livestock research must begin with a well conceived problem statement and employ appropriate data acquisition tools and analytical techniques to accomplish the research objective.\  These requirements are especially critical in addressing animal distribution.\  Tools and statistics used to describe the plant-livestock interface must consider that foraging is highly place dependent, foraging is not a random process and livestock foraging mainly occurs in groups.\  Since animal movement implies consecutive locations, each the result of a host of interactions between the animal and its surroundings, classical agronomic statistics may not provide the optimum analytical tools to address spatially related phenomena. By far the greatest amount of research on quantitative tools to understand the use of space by animals has come from the wildlife community and more recently from ecologists exploring the distribution of both animal and plant species over large geographic areas.\  However, interest in geospatial data analysis methods is also found among animal-range scientists, primarily because new electronic technologies make it possible to accumulate data from free-ranging animals in seconds or less.\  Therefore, the rate at which data can now be collected produces inordinate amounts of information that must be correctly analyzed. Consecutive animal locations on a landscape are not statistically independent; therefore, autocorrelation is no longer a theoretical but real concern and must be addressed in animal distribution analyses.\  This paper presents an overview of research that affects landscape use together with possible geospatial tools that can be used when evaluating free-ranging animal distributions.\  Geospatial methodology is not trivial nor is it a mature field, but rather is evolving; therefore, the range-animal scientist should work as a team member with other disciplines including but not limited to statisticians, modelers, computer scientists, cognitive scientists, physicists, sociologists, and possibly geographers when attempting to understand animal distribution.\  Literature referenced in this paper is comprehensive in breath but not exhaustive in detail and thus serves as a beginning point for those wanting to know what has already been researched concerning livestock distribution on landscapes.

}, author = {D.M. Anderson} } @conference {50067, title = {Gathering cows using virtual fencing methodologies}, booktitle = {62nd Society for Range Management Annual Meeting}, year = {2009}, month = {02/2009}, pages = {2030-4}, address = {Albuquerque, NM}, abstract = {

Free-ranging livestock are classically controlled by herders. Holding, moving, or gathering free-ranging cattle requires flexible husbandry practices for efficient and effective low-stress animal management. Behavioral theory and practical experience indicates cattle can be taught to respond to auditory cues. Preliminary research has demonstrated that cows can be gathered autonomously using recorded audio cues associated with manual gathering. However, efficient gathering requires movement in the proper direction. Therefore, we believe using audio cues administered from directional virtual fencing (DVF\™) equipment can facilitate proper animal orientation and facilitate the gathering of animals with minimal human intervention. Results from applying directional audio cues to free-ranging cows using hard- and software developed by the Massachusetts Institute of Technology (MIT) will be discussed in light of how many animals in a herd potentially need to be instrumented in order to successfully gather the entire group.

}, keywords = {DVF, free-ranging, SRM}, author = {D.M. Anderson and D. Rus} } @conference {50078, title = {Grazing systems research: Focusing on the managers-introduction}, booktitle = {62nd Society for Range Management Annual Meeting}, year = {2009}, month = {02/2009}, pages = {21-1}, publisher = {Society for Range Management}, organization = {Society for Range Management}, address = {Alb., NM}, abstract = {

Translating experimental results into management guidelines or as bases for specific decisions presents a substantial challenge for scientists, advisors and land managers. While inductive reasoning can be a valuable tool in developing general guidelines, particular wholly science-based relationships, taken out of context, may not translate well or may be misleading if improperly applied. For example, substantial effort has been expended on glasshouse, small plot and small paddock scale responses of individual plants, populations and communities to varying frequency and intensity of defoliation and other direct impacts of livestock grazing (trampling, dunging). There is little reason to suspect that these soil and vegetation responses are not scalable to commercial grazing applications if interpreted within the known and applicable bounds of climate and soils. Individual grazing animal attributes discerned experimentally, such as species and community selectivity, forage intake and nutrition related performance (gain/hd, gain/ha) are likewise valid at more extensive scales and generally applicable to policy and management decisions. Properties and relationships that emerge only at commercial scales, such as landscape scale animal distribution and forage selectivity, herd management (genetics, reproduction attributes, hygiene etc), financial management (investment portfolios), and range management (improvements, response to drought) must be investigated, analyzed and interpreted at coarser scales to have meaning. Research and development should clearly identify these variables, their tests and scaleable interpretations to identify their limits of application for management and decision making.

}, keywords = {abstract, grazing systems, mangers-introduction, SRM}, author = {Joel R. Brown and Kris Havstad} } @conference {50081, title = {Grazing effect on woody plant recruitment in a Sonoran Desert grassland across space and time}, booktitle = {US International Association for Landscape Ecology}, year = {2009}, month = {04/2009}, publisher = {US, IALE}, organization = {US, IALE}, address = {Snowbird, Utah}, abstract = {

Livestock grazing is a commonly cited factor contributing to shrub encroachment in savannas and grasslands. Patterns of woody plant proliferation are known to influence rates of erosion and spread of disturbance and are of practical importance to livestock management with regard to forage distribution and abundance. However, the effects of grazing on woody plant population dynamics and stand structure are poorly understood, owing to a paucity of long-term, spatially-explicit data. We explored the spatial patterns of distribution and recruitment for velvet mesquite (Prosopis velutina) using field surveys spanning 74 years (1932, 1948, and 2006) on areas grazed by livestock since the late 1800s and protected from livestock since 1932. Univariate analyses with Ripley\’s K and neighborhood density functions (NDF) revealed mesquite plants were randomly distributed in 1932. In 1948, following 16 years of protection from livestock, plants on the protected area were clustered at all distances (1 to 20m), while mesquite on the grazed area were clustered at short distances (1 to 4m) only. In 2006, mesquite on the protected area remained clustered at all distances, with a marked peak in clustering at short distances (1 to 4m), whereas mesquite on the grazed area were randomly distributed. Bivariate analyses with Ripley\’s K and NDF indicated that juvenile mesquite plants (\<1m height) were significantly clustered around adult plants from 2 to 5m on the protected area in 2006; but there were no significant patterns of association between juveniles and adults on the grazed area through time. Previous analyses revealed that spatial autocorrelation in mesquite density did not deviate from random on the grazed area, whereas associations on the protected area became increasingly positive. Grazing influenced recruitment-driven changes in population structure from 1932 to 2006 and protection from livestock facilitated formation of high density shrub clusters and open areas generating high spatial heterogeneity.

}, keywords = {erosion, grasslands, livestock management, point pattern analysis, proliferation, Santa Rita Experimental Range, savannas, shrub encroachment, spatial ecology, velvet mesquite, woody}, author = {Dawn M. Browning and Janet Franklin and Steven R. Archer} } @inbook {50085, title = {Grasslands in the Borderlands. Understanding coupled natural-human systems and transboundary conservation}, booktitle = {Conservation of Shared Environments. Learning from the United States and Mexico}, year = {2009}, month = {2009}, pages = {188-203}, publisher = {University of Arizona Press}, organization = {University of Arizona Press}, chapter = {12}, address = {Tucson, AZ}, abstract = {Grasslands are one of the shared ecosystems that dominate the heart of the North American continent. Among these are the Chihuahuan Desert grasslands that are undergoing a rapid transition to desertified, arid scrub conditions. Policy-driven landuse changes are reducing their capacity to maintain biodiversity, ecosystem services, and human well-being. In northwestern Chihuahua, and adjoining New Mexico, Arizona and Texas, degradation occurred differentially on either side of the border with degradation in the United States preceding that in Mexico, but becoming more pronounced in some parts of Mexico during the last two decades. Degradation patterns in the United States can inform Mexican conservation efforts, while relatively intact Mexican ecosystems provide valuable insights into functional grassland systems. Our collaborative socio-ecological study of the patterns and processes governing ecological change is guiding grassland recovery with the goal of maintaining biodiversity that appears necessary to reinstate lost ecosystem services and grassland productivity on which human population{\textquoteright}s in the transbounday region depend. As this chapter discusses, prairie dogs in this region exhibit the characteristics of a keystone species and are important ecosystem engineers that maintain northern Chihuahuan grasslands. They are critical for the maintenance of biodiversity and support grassland ecosystem functioning, resulting in important benefits for humans. The natural process of prairie dogs supporting ecosystem function creates ecosystem services essential for human well-being. This process is disrupted by poor land management (i.e., governmental policies that promote cattle overgrazing) resulting in environmental degradation that results in a loss of biodiversity, alteration of ecosystem function, and reduction of ecosystem services. In this chapter we present an approach to overcome the negative cycle of overgrazing, and discuss how this approach could be implemented bi-nationally.}, keywords = {borderlands, grasslands, Mexico, US}, url = {/files/bibliography/09-028.pdf}, author = {G. Ceballos and List, R. and A.D. Davidson and E.L. Fredrickson and Sierra Corona, R. and Martinez, L. and Jeffrey E. Herrick and Pacheco, J.}, editor = {Lopez-Hoffman, L. and McGovern, E.D. and Varady, R.G. and Flessa, K.W.} } @article {50118, title = {Grazing intensity on vegetation dynamics of a typical steppe in Northeast Inner Mongolia}, journal = {Rangeland Ecology and Management}, volume = {62}, number = {4}, year = {2009}, month = {07/2009}, pages = {328-336}, chapter = {328}, abstract = {

Vegetation features radiating from residential areas in response to livestock grazing were quantified for an arid steppe rangeland in the Keshiketeng Banner, Chifeng Prefecture in northeastern Inner Mongolia in 2004 and 2006. The aim of this study was to estimate grazing impacts on the vegetation dynamics of these historical grazed ecosystems. Grazing intensities were classified as reference area (RA), light (LG), moderate (MG) and heavy (HG) according to the vegetation utilization across the study area. Rangelands were studied along a grazing gradient, where characteristics of plant communities, heights of dominant species, above ground vertical structures and below ground biomass were investigated. Along this grazing gradient vegetation changed from the original plant dominant species Leymus chinensis (Trin.) Tzvel to a semi-subshrub species Artemisia frigida Willdin moving from the reference area (RA) to the region around the settlement. Canopy coverage, above ground productivity, and the number of perennial species declined moving towards the residential area. Heights of five dominant species, except for Stipa grandis P. Smirn, declined with increases in grazing intensity. Vertical structure above ground in the RA treatment showed a more resilient model than the other treatments. There were no difference in root biomass in the top 1 m of soil showed no difference (P \> 0.05) between the RA treatment and the area immediately around settlement (HG treatment). Generally, we found that the intensity of grazing disturbance did not exceed the tolerance of the rangeland ecosystem within LG treatment. However, vegetative conditions in HG treatment became worse with increases in grazing pressure. Rangelands in this arid steppe are under tremendous threats due to excessive forage utilization that can not be considered as sustainable practices.

}, keywords = {forage utilization, grazed ecosystem, Inner Mongolia grasslands, plant-herbivore interactions}, url = {/files/bibliography/09-016.pdf}, author = {Liang, Y. and G. Han and Huakun Zhou and Mengli Zhao and Snyman, H.A. and Shan, D. and Kris Havstad} } @inbook {50197, title = {Ground-based snowfall and snowpack measurements}, booktitle = {Principles of Snow Hydrology}, year = {2008}, month = {July 2008}, pages = {76-117}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, address = {Cambridge, NY}, abstract = {

One of the most fundamental aspects of snow hydrology is an understanding of the processes that lead to snowfall and the eventual distribution of a snowpack on the landscape. The factors that lead to the formation of snowfall are generally discussed in the beginning sections of the chapter. Since snowfall once formed, unlike rain, is quite easily borne by the wind and redistributed across the landscape before finally coming to rest to form a snowpack, the basic principles controlling blowing snow are also reviewed. Finally, the interception of snow by vegetation, which can have a profound effect on the amount and timing of snow that accumulates into a snowpack beneath a plant canopy, is described in the final section of the chapter.

}, keywords = {distribution, hydrology, snow, snowfall, snowpack}, url = {http://www.cambridge.org/us/academic/subjects/earth-and-environmental-science/hydrology-hydrogeology-and-water-resources/principles-snow-hydrology}, author = {D. DeWalle and A. Rango} } @article {50237, title = {Geographic patterns of ground-dwelling arthropods across an ecoregional transition in the North American Southwest}, journal = {Western North American Naturalist}, volume = {68}, number = {1}, year = {2008}, note = {//NMSU,USDA//LTER V//entered 04/03/2008, pdf available}, month = {2008}, pages = {83-102}, abstract = {

We examined the biogeographic patterns of ground-dwelling arthropod communities across a heterogeneous semiarid region of the Southern Rio Grande Rift Valley of New Mexico. Our 3 sites included portions of 5 ecoregions, with the middle site a transition area where all ecoregions converged. We addressed the following 3 questions: (1) Do the species assemblage patterns for ground arthropods across habitats and sites conform to recognized ecoregions? (2) Are arthropod assemblages in distinct vegetation-defined habitats within an ecoregion more similar to each other or to assemblages in similar vegetation-defined habitats in other ecoregions? (3) Is there a detectable edge effect with increased arthropod diversity in the area of converging ecoregions? We encountered 442 target arthropod species from pitfall traps operating continuously for 7 years over a series of different habitats at each of the 3 sites. We examined geographic distributions of spider and cricket/grasshopper species in detail, and they showed affinities for different ecoregions, respectively. Each habitat within a study site supported a unique overall arthropod assemblage; nevertheless, different habitats at the same site were more similar to each other than they were to similar habitats at other sites. Overall arthropod species richness was greatest in the area where all 5 ecoregions converged. Arthropod species and their geographic distributions are poorly known relative to vascular plants and vertebrate animals. Findings from this research indicate that ecoregional classification is a useful tool for understanding biogeographic patterns among arthropods.

}, keywords = {arthropod, biogeography, arthropod, ecotones, arthropod, geographic distribution, arthropod, ground-dwelling, arthropod, species richness, article, cricket, geographic distribution, grasshopper, geographic distribution, journal, spider, geographic distribution}, doi = {10.3398/1527-0904(2008)68[83:GPOGAA]2.0.CO;2}, url = {files/bibliography/JRN00501.pdf}, author = {David C. Lightfoot and S.L. Brantley and C.D. Allen} } @article {50240, title = {The global distribution of atmospheric phosphorus deposition and anthropogenic impacts}, journal = {Global Biogeochemical Cycles}, volume = {22}, year = {2008}, pages = {GB4026}, abstract = {

[1] A worldwide compilation of atmospheric total phosphorus (TP) and phosphate (PO4) concentration and deposition flux observations are combined with transport model simulations to derive the global distribution of concentrations and deposition fluxes of TP and PO4. Our results suggest that mineral aerosols are the dominant source of TP on a global scale (82\%), with primary biogenic particles (12\%) and combustion sources (5\%) important in nondusty regions. Globally averaged anthropogenic inputs are estimated to be \~{}5 and 15\% for TP and PO4, respectively, and may contribute as much as 50\% to the deposition over the oligotrophic ocean where productivity may be phosphorus-limited. There is a net loss of TP from many (but not all) land ecosystems and a net gain of TP by the oceans (560 Gg P a-1). More measurements of atmospheric TP and PO4 will assist in reducing uncertainties in our understanding of the role that atmospheric phosphorus may play in global biogeochemistry.

}, keywords = {anthropogenic impacts/ atmospheric deposition, phosphorus deposition}, doi = {10.1029/2008GB003240}, url = {files/bibliography/JRN00518.pdf}, author = {Mahowald, N. and Jickells, T. D. and Baker, A. R. and Artaxo, P. and Benitez-Nelson, C. R. and Gilles Bergametti and Bond, T. C. and Chen, Y. and Cohen, D. D. and Herut, B. and Kubilay, N. and Losno, R. and Luo, C. and Maenhaut, W. and K. McGee and Gregory S. Okin and Siefert, R. L. and Tsukuda, S.} } @article {50366, title = {Global-scale similiarities in nitrogen release patterns during long-term decomposition}, journal = {Science}, volume = {315}, year = {2007}, note = {//NMSU//LTER V//Study: LIDET//entered 02/15/2007}, month = {2007}, pages = {361-364}, abstract = {

Litter decomposition provides the primary source of mineral nitrogen (N) for biological activity in most terrestrial ecosystems. A 10-year decomposition experiment in 21 sites from seven biomes found that net N release from leaf litter is dominantly driven by the initial tissue N concentration and mass remaining regardless of climate, edaphic conditions, or biota. Arid grasslands exposed to high ultraviolet radiation were an exception, where net N release was insensitive to initial N. Roots released N linearly with decomposition and exhibited little net N immobilization. We suggest that fundamental constraints on decomposer physiologies lead to predictable global-scale patterns in net N release during decomposition.

}, keywords = {article, decomposition, leaf litter, decomposition, root, journal, LIDET, long-term decomposition, nitrogen}, doi = {10.1126/science.1134853 }, url = {files/bibliography/JRN00478.pdf}, author = {William Parton and Silver, Whendee L. and Ingrid C. Burke and Grassens, Leo and M. Harmon and Currie, William S. and King, Jennifer Y. and Adair, E. Carol and Brandt, Leslie A. and Hart, Stephen C. and Fasth, Becky} } @conference {50372, title = {Genetic diversity studies of Bouteloua eriopoda (Black grama grass) in southern New Mexico: Spatial and temporal variations}, booktitle = {American Society of Plant Biologists}, year = {2007}, month = {July 7-11, 2007}, address = {Chicago, IL}, abstract = {Bouteloua eriopoda (black grama grass) is a drought-tolerant, C4, warm-season grass, native to the southwestern region of the United States and Mexico. Its nutritive properties and late dormancy (it maintains green stems well into winter) make it very good forage for livestock in the region. However, black grama appears to be very susceptible to rangeland disturbances, including overgrazing, severe drought, and human activity, and its overall abundance has decreased sharply in the last 50-100 years. This decline, along with its predicted lifespan (30-40 years), anecdotally low seedling establishment rate, and ability to reproduce clonally by stolons, may have lead to low genetic variability, causing a decreased ability to adapt to disturbances and potential climate change. In the work presented, amplified fragment length polymorphism (AFLP) was performed on two populations of B. eriopoda in south central New Mexico, collected from the Jornada Experimental Range (Dona Ana County) and the Otero Mesa Grasslands (Otero County) to help measure the extent of genetic diversity within and across these populations. Ten additional black grama herbarium samples dating from the 1920s to the 1990s were also tested in an attempt to measure loss of genetic diversity. Our results show that black grama grass appears to have the genetic variability of an outcrossing grass. Data will also be presented that measure the genetic distances, differences, and similarities between the spatial and temporal populations.}, keywords = {black grama grass, Bouteloua eriopoda, grass, overgrazing, rangeland, southwestern}, author = {Potenza, C.L. and A. L. Slaughter and Yeater, K.M. and J.R. Barrow} } @article {JRN54980, title = {Global Warming Effects on Snowfields and Water Suppy Evaluated Using Snowmelt Modeling and Normalized Annual Data}, journal = {Western Snow Conference 2007}, year = {2007}, pages = {69-76}, chapter = {69}, abstract = {

The effect of global warming on the snow cover and runoff in mountain basins can be evaluated by comparing present and future conditions modeled for a climate scenario. Rather than use a single historical year to represent today{\textquoteright}s climate, an improved method is presented which consists of deriving a so-called normalized year. In the Rio Grande basin near Del Norte, Co (2414 km2, 2432-4215 m a.s.l.) the effect of a hypothetical temperature increase of +4{\textdegree}C on the snow cover and runoff as experienced in hydrological year 1979 was evaluated. Because 1979 has relatively frequent temperatures below -4{\textdegree}C, snowmelt as well as conversion of snowfall to rainfall was limited during winter. Consequently, the redistribution of runoff from summer to winter was not as significant as evaluated in other basins. The data set of 1979 was modified by applying the so-called normalized temperatures for the period 1957-1994. The predicted future snow conditions in the normalized year show a complete disappearance of snow in the lowest elevation zone (2432 {\textendash} 2929 m a.s.l.) on April 1, due to an increased snowmelt in the winter. The resulting winter runoff which increased from 7.6\% to 12.8\% of the annual total, in 1979, now increases from 11.7\% to 24.2\% of the normalized annual total. In evaluation of the impact of climate change in mountain basins, more realistic results can be expected if today{\textquoteright}s climate is represented by normalized data of several decades instead of one single year.

}, url = {files/bibliography/Rango2007-03.pdf}, author = {A. Rango and J. Martinec and R. T. Roberts} } @article {50376, title = {Global desertification: building a science for dryland development}, journal = {Science}, volume = {316}, year = {2007}, note = {//??//LTER-V//entered 08/15/2007}, month = {2007}, pages = {847-851}, abstract = {

In this millennium, global drylands face a myriad of problems that present tough research, management, and policy challenges. Recent advances in dryland development, however, together with the integrative approaches of global change and sustainability science, suggest that concerns about land degradation, poverty, safeguarding biodiversity, and protecting the culture of 2.5 billion people can be confronted with renewed optimism. We review recent lessons about the functioning of dryland ecosystems and the livelihood systems of their human residents and introduce a new synthetic framework, the Drylands Development Paradigm (DDP). The DDP, supported by a growing and well-documented set of tools for policy and management action, helps navigate the inherent complexity of desertification and dryland development, identifying and synthesizing those factors important to research, management, and policy communities.

}, keywords = {DDP, degradation, desertification, development, Drylands Development Paradigm, global}, doi = {10.1126/science.1131634 }, url = {/files/bibliography/07-012.pdf}, author = {J. F. Reynolds and D. Mark Stafford Smith and E. Lambin and B.L. Turner II and Mortimore, Michael and Batterbury, Simon P.J. and Downing, Thomas E. and Dowlatabadi, Hadi and Roberto J. Fern{\'a}ndez and Jeffrey E. Herrick and E. Huber-Sannwald and Jiang, Hong and Leemans, Rik and Lynam, Tim and F. Maestre and M. Ayarza and Brian Walker} } @mastersthesis {50399, title = {Geomorphic-banded vegetation relationships in the northern Chihuahuan Desert}, year = {2007}, note = {//??//LTER-V//entered 08/15/2007ProCite field[12]: Not in File}, month = {2007}, school = {New Mexico State University}, address = {New Mexico State University}, keywords = {dissertation, geomorphology, banded vegetation, plant, banded vegetation, thesis}, author = {Weems, Stacey L.} } @inbook {50451, title = {Grazing Livestock Management in an Arid Environment}, booktitle = {Structure and Function of a Chihuahuan Desert Ecosystem: The Jornada Basin Long-Term Ecological Research Site}, year = {2006}, month = {July 1, 2006}, pages = {266-277}, publisher = {Oxford University Press}, organization = {Oxford University Press}, chapter = {13}, address = {New York}, abstract = {The history of livestock grazing in the Jornada Basin of southern New Mexico is a relatively recent story, but one of profound implications. For four centuries this region has supported a rangeland livestock industry, initially sheep, goats, and cattle, but primarily beef cattle for the past 130 years. Throughout this brief history of a domesticated ruminant in an ecosystem without a significant presence of large hoofed mammals as part of its evolutionary development, the livestock industry has continually grappled with high degrees of temporal and spatial variation in forage production. Management of this consumptive use, whether during Spanish, Mexican, United States Territorial, United States federal, or New Mexican governments, has constantly reaffirmed the need for grazing management to be flexible and responsive to the stress of droughts. The history of anecdotal experiences has been more recently augmented by scientific investigations first initiated in 1915. This chapter outlines the general history of livestock in this region, the historical specifics of ranching in the Jornada Basin, and resulting principles of grazing management derived from nearly a century of studies on grazing by large, domesticated herbivores.}, keywords = {Chihuahuan Desert, grazing, Jornada Basin, livestock management, LTER, synthesis book}, url = {/files/bibliography/06-064.pdf}, author = {Kris Havstad and E.L. Fredrickson and L. Huenneke}, editor = {Kris Havstad and L. Huenneke and W. H. Schlesinger} } @conference {50472, title = {Genetic characterization of uncultured fungal endophytes from Bouteloua Eriopoda and Atriplex}, year = {2006}, month = {June 6-8, 2006}, address = {Cedar City, UT}, abstract = {

Obligate fungal endophytes form cryptic communities in vascular plants which can defy detection and isolation by conventional methods. Molecular detection by PCR amplification of fungal DNA sequences alone is insufficient, since target endophyte sequences are unknown and quite similar to sequences already characterized as plant DNA. We have successfully separated fungal and plant ribosomal DNA sequences by amplifying plant-extracted DNA with polymerase chain reaction, and separating sequences with denaturing gradient gel electrophoresis (DGGE). The resulting electrophoregrams produce specific bands unique for each organism present in a specific plant-endophyte community. This method has successfully identified endophytes in B. eriopoda and A. canescens, and has tracked these endophytes as they are transferred to novel host plants. The detection and monitoring capabilities of DGGE make it a valuable tool for discovery, characterization, and monitoring of rangeland endophytes.

}, keywords = {Atriplex, Bouteloua, endophytes, Eriopoda, fungal}, author = {M.E. Lucero and J.R. Barrow and Ruth L. Sedillo and P. Osuna-Avila and I. Reyes-Vera} } @proceedings {50473, title = {Genetic characterization of uncultured fungal endophytes from Bouteloua eriopoda and Atriplex canescens}, year = {2006}, month = {2006}, abstract = {

Obligate fungal endophytes form cryptic communities in vascular plants which can defy detection and isolation by microscopic examination of reproductive structures. Molecular detection by PCR amplification of fungal DNA sequences alone is insufficient, since target endophyte sequences are unknown and difficult to distinguish from sequences already characterized as plant DNA. We have successfully separated fungal and plant ribosomal DNA sequences by amplifying plant-extracted DNA with polymerase chain reaction, and separating sequences with denaturing gradient gel electrophoresis (DGGE). The resulting electrophoregrams theoretically produce specific bands unique for each organism present in a plant-endophyte community. This method has successfully identified endophyte sequences in Bouteloua eriopoda and A.triplex canescens, and has tracked these endophytes as they are transferred to novel host hosts.

}, author = {M.E. Lucero and J.R. Barrow and P. Osuna-Avila and I. Reyes-Vera and Ruth L. Sedillo} } @conference {50510, title = {Guidelines for sampling for dynamic soil properties for soil survey updates}, booktitle = {Western Society of Soil Science}, year = {2006}, month = {June 19-23, 2006}, address = {Park City, UT}, abstract = {Dynamic soil property data can be collected during soil survey updates to add value to soil survey products and meet users{\textquoteright} needs. Producers and land managers need information about soil and ecosystem change in order to plan for long-term productivity, conduct monitoring and assessments and predict management effects on soil. Data collection technologies that can be used in the soil survey program are, however, not fully developed. NRCS is now developing guidelines in cooperation with the Agricultural Research Service Jornada Experimental Range, National Park Service, Forest Service and Bureau of Land Management. This poster describes the steps for designing dynamic soil properties projects.}, keywords = {guidelines, sampling, soil survey}, author = {A.J. Tugel and J.P. Ward and Jeffrey E. Herrick and Biggam, P. and C. Seybold and M.D. Remmenga and Benham, E.C. and Brandon T Bestelmeyer and A. Moore and Young, F.} } @proceedings {50540, title = {Geometric-Optical Modeling of Desert Grassland Canopy Structure with MISR}, year = {2005}, month = {October 17, 2005}, pages = {141-143}, address = {Bejing, China}, abstract = {A new method is described for the retrieval of fractional cover of large woody plants (shrubs) at the landscape scale using moderate resolution multiangle remote sensing data from the Multiangle Imaging SpectroRadiometer (MISR) and an hybrid geometric-optical (GO) canopy reflectance model. The major difficulty in applying such models in desert grasslands if the spatially dynamic nature of the combined soil and understory background reflectance. The best method found was multiple regression on the weights of a kernel-driven model and MISR nadir camera blue, green, and near infra-red bidrectional reflectance factors. The results of forward modeling for a 5.15 km2 area in the USDA, ARS Jornada Experimental Range (n=441) showed excellent agreement with the MISR data in both shape and magnitude. Inversion of the model allowed estimation of fractional shrub cover with an RMSE of 0.03.}, keywords = {MISR, remote, remote sensing, sensing, shrubs}, url = {/files/bibliography/05-051Proc.pdf}, author = {M. Chopping and J. V. Martonchik and A. Rango and Debra C. Peters and L. Su and Andrea S. Laliberte} } @article {50584, title = {Grazing Impacts on Spatial Distribution of Soil and Herbaceous Characteristics in an Australian Tropical Woodland}, journal = {Agroforestry Systems}, volume = {65}, number = {2}, year = {2005}, month = {2005}, pages = {137-150}, abstract = {Land condition in northern Australia can be easily degraded by grazing or grazing in combination with drought. These areas require the use of grazing systems that allow persistence of native tussock grasses, and maintenance of soil condition. However, there is little information available on best level of utilization, or how plants and soils will respond to grazing and drought. This study examined effects of six different grazing regimes (based on timing and grazing intensity), applied over five (n=4) and 15 (n=2) years, on herbaceous vegetation (standing crop, basal area, size and spacing of grass tussocks) and soil properties (soil C, total N, total P, and soil-borne plant matter [roots and surface litter]) around grass tussocks in replicate (n=2) paddocks of eucalypt woodland in northern Queensland. Grass tussocks influenced soil C and total N at small (<30 cm) spatial scales, and applied grazing pressures significantly (P<0.05) affected all soil properties except total P. Concentrations of N and C were highest at locations in close proximity to plants, and levels declined under heavier grazing pressures. These paddocks also had less standing crop, smaller tussocks, and more widely dispersed surviving plants. Further, areas with high amounts of soil C, N and roots-litter were smaller and more widely dispersed under heavy grazing. North Australian landscapes have limited resistance to disturbance, or resilience available for recovery. As such, the effects of disturbance should be monitored by a combination of plant (basal area, plant spacing) and soil characteristics (total N, soil borne plant matter) that can detect the degradation process at the earliest stage possible.}, keywords = {Eucalypt woodlands, grazing pressur, land condition, plant-soil interactions, silvopasture, soil properties}, url = {/files/bibliography/05-021.pdf}, author = {Northup, B.K. and Joel R. Brown and A.J. Ash} } @proceedings {50635, title = {A general classification of vegetation dynamics for Chihuahuan Desert management models}, year = {2004}, month = {2004}, abstract = {We briefly describe a new conceptual approach to describing vegetation dynamics based on multiple scales of vegetation/soil pattern and processes and cross-scale interactions among grass loss in patches, patch connectivity and sediment/water flux regulation, and climate-forcing functions. This approach is based on a preliminary classification of transitions into five broad classes including: (1) size oscillation of grasses, (2) loss and recolonization of grasses, (3) loss of grasses with replacement by shrubs, (4) spatial reorganization of grass/shrub patches, and (5) cascading grass-shrub transitions that spread from small to broad scales. This classification links spatial and temporal patterns with ecological processes and monitoring strategies.}, author = {Brandon T Bestelmeyer and Jeffrey E. Herrick and Kris Havstad and Joel R. Brown} } @article {50661, title = {Gully seeder for reseeding rangeland and riparian areas}, journal = {Journal of Range Management}, volume = {57}, year = {2004}, month = {July 1, 2004}, pages = {399-401}, abstract = {

Traditional methods of reseeding degraded arid and semiarid rangeland are expensive and frequently unsuccessful due to high rates of seed predation and seedling mortality. A runoff-based method is described that protects seeds from predation and degradation until soil moisture is available and then deposits them in favorable microsites for germination and establishment. Seeds are placed in three 2 cm diameter x 8 cm PVC tubes. The small tubes are capped with crepe paper and glued inside a 7.5 cm diameter x 15 cm long tube that is capped with hardware cloth. The tubes are placed in small rills, gullies, arroyos or riparian areas and the seeds are released sequentially from the three tubes as flow depth increases. Seeds are deposited beneath piles of litter where soil moisture and temperature are more favorable for seedling establishment.

}, keywords = {article, articles, journal, journals, land degradation, rangeland, revegetation, remediation, restoration, restoration, grassland, revegetation, riparian, reseeding, seeding methods, technique, gully seeder, technique, remediation, technique, seeding}, url = {/files/bibliography/04-004.pdf}, author = {Gutierrez, L.R. and Jeffrey E. Herrick and G.B. Donart} } @article {50678, title = {Geomorphic features and soil formation of arid lands in northeast Jordan}, journal = {Archives of Agronomy and Soil Science}, volume = {50}, year = {2004}, note = {//NONE//NONE//}, month = {2004}, pages = {607-615}, author = {Sa{\textquoteright}eb Khresat and Rawajfih, Z. and B. J. Buck and Curtis H. Monger} } @proceedings {50746, title = {Grazing in complex environments: The details matter}, year = {2003}, month = {January 18-19, 2}, pages = {1-6}, address = {Albuquerque, NM}, abstract = {Rangeland ecosystems are complex environments. Their physical, biological, economic, and social elements are driven by thousands of variables with millions, if not billions, of interactions. Because our understanding of these systems is incomplete, at best, it has been very difficult to develop predictive models with sufficient precision to describe how these systems will behave in response to management. Within this setting, livestock grazing is a reasonable use on many rangelands, although it may not be appropriate in some environments. The sustainability of livestock grazing in western rangeland environments is dependent upon appropriate management of this activity and requires an understanding of the basic workings of these ecosystems{\textquestiondown}of key processes related to soils, plants, and animals. These processes vary with different environments, conditions, annual cycles, histories, production inputs, and other factors. Many of these considerations are subject to variations in space and time. Not all landscapes can be managed alike; good grazing management requires close attention to the details. In order to manage grazing in a truly adaptive and sustainable manner, we need to be able to recognize what is present in a given system, to understand what is possible for that system, and to monitor our effects.}, url = {http://quiviracoalition.org/Detailed/On-Line_Store/Conference...dings/The_New_Ranch_at_Work_198.html}, author = {Brandon T Bestelmeyer and Joel R. Brown and Kris Havstad} } @proceedings {50820, title = {The genesis of range science with implications for current development policies}, year = {2003}, month = {July 26-August 1}, pages = {1976-1985}, address = {Durban, South Africa}, abstract = {At the opening of the new millennium, both range science and pastoral development find themselves in a state of flux. Recent decades have witnessed widespread criticism of pastoral development programs implemented in the latter half of the twentieth century (Agrawal 1998, Ferguson 1994, Hary et al. 1996). Meanwhile, ecological research has cast doubt on the Clementsian paradigm that informed range science and policy for most of the last century (Vesk and Westoby, 2001; Westoby, Walker and Noy-Meir, 1989). The need to reassess and reconfigure both the theory and practice of pastoral/range management is widely acknowledged (Mearns, 2002; Turner, 1998). Curiously, however, little attention has been paid to the historical origins of the range science-development nexus in the United States during the late nineteenth and early twentieth centuries from which emerged the model for much subsequent development work. As scientists, policy makers, and pastoralists work to find new models, a consideration of this history provides important perspective and lessons for the challenges ahead.}, url = {/files/bibliography/03-029.pdf}, author = {N. F. Sayre and Maria Fern{\'a}ndez-Gim{\'e}nez} } @conference {50899, title = {A GIS model of soil processes for arid land management}, booktitle = {87th Annual Meeting, Ecological Society of America}, year = {2002}, month = {August 4-9, 2002}, pages = {373}, address = {Tucson, AZ}, abstract = {There is a growing need at the state and federal management agency levels to make decisions based on ecological processes across the landscape. Arid and semiarid lands around the world are thought to be best understood in terms of their soil resources. One soil process that influences water infiltration and storage, soil stsructure, and plant recruitment is biopedturbation. These movements of soil by animals were monitored on plots established in dominant vegetation and soil types on the USDA-ARS Jornada Experimental Range over a 3-year period. We analyzed the results in a spatially explicit GIS model that predicts seasonal abundances and types of disturbances throughout the Dona Ana basin.}, author = {Aaron Killgore and Walter G. Whitford} } @conference {50918, title = {Grazing effects on microtopography in a desert grassland}, booktitle = {87th Annual Meeting, Ecological Society of America}, year = {2002}, month = {August 4-9, 2002}, pages = {398}, address = {Tucson, AZ}, abstract = {Coincident with a worldwide increase in the abundance of woody plants within former grasslands, desert grasslands throughout the southwestern U.S. have experienced a substantial increase in the abundance of shrubs during the last century. The displacement of grasslands with grass-shrublands has had important implications for ecosystem carbon cycling and rates of carbon sequestration. Building on a history of biogeochemistry research conducted at the Jornada Experimental Range in southern New Mexico, we measured and modelled aboveground and belowground carbon storage in black grama grasslands (Bouteloua eriopoda) and mesquite (Prosopis glandulosa) and creosotebush (Larrea tridentata) shrublands across the Jornada basin. We combined the simulation modeling predictions of the CENTURY model with data from recovered historical vegetation maps of 1858, 1915, 1928 and modern vegetation maps. Our results support the hypothesis that shrub encroachment into grasslands increases storage of belowground carbon. Landscape-level mapped estimates of carbon pools indicate that the desert grassland ecosystem of the Jornada basin may have served as a carbon sink during the last century.}, author = {M. S. Nash and E. Jackson and Walter G. Whitford} } @article {50945, title = {Graminivory by Dipodomys ordii and Dipodomys merriami on four species of perennial grasses}, journal = {The Southwestern Naturalist}, volume = {47}, number = {2}, year = {2002}, month = {June 1, 2002}, pages = {276-281}, abstract = {

Kangaroo rats have been described as primarily granivorous; however, they also consume green vegetation. We investigated selectivity of grasses by kangaroo rats (Dipodomys ordii and D. merriami) presented with four common perennial grass species from the Jornada Basin in the Chihuahuan Desert. All grass species offered were utilized, and there were differences in utilization. Our results suggest that water content may underlie these differences, although other factors are not excluded. Merrian\&$\#$39;s kangaroo rats removed more tillers from each tussock of grass than Ord\&$\#$39;s kangaroo rat. Ord\&$\#$39;s kangaroo rat may select grasses with higher water content per tiller.

}, doi = {10.2307/3672915}, url = {/files/bibliography/02-085.pdf}, author = {Sipos, M. and C.A. Anderson and Walter G. Whitford and W. R. Gould} } @inbook {51038, title = {Global environmental change: Effects on biodiversity}, booktitle = {Conservation Biology: Research Priorities for the Next Decade}, year = {2001}, note = {//???//LTER IV//ProCite field[6]: In}, month = {2001}, pages = {175-223}, publisher = {Island Press}, organization = {Island Press}, address = {Washington, D. C.}, keywords = {book, books, chapter, chapters, global change, biodiversity, report, reports}, author = {W. H. Schlesinger and Clark, J. S. and Mohan, J. E. and Reid, C. D.}, editor = {Soule, M. E. and Orians, G. H.} } @article {51113, title = {Global biodiversity scenarios for the year 2100}, journal = {Science}, volume = {287}, year = {2000}, note = {//?//LTER III//}, month = {2000}, pages = {1770}, abstract = {

Scenarios of changes in biodiversity for the year 2100 can now be developed based on scenarios of changes in atmospheric carbon dioxide, climate, vegetation, and land use and the known sensitivity of biodiversity to these changes. This study identified a ranking of the importance of drivers of change, a ranking of the biomes with respect to expected changes, and the major sources of uncertainties. For terrestrial ecosystems, land-use change probably will have the largest effect, followed by climate change, nitrogen deposition, biotic exchange, and elevated carbon dioxide concentration. For freshwater ecosystems, biotic exchange is much more important. Mediterranean climate and grassland ecosystems likely will experience the greatest proportional change in biodiversity because of the substantial influence of all drivers of biodiversity change. Northern temperate ecosystems are estimated to experience the least biodiversity change because major land-use change has already occurred. Plausible changes in biodiversity in other biomes depend on interactions among the causes of biodiversity change. These interactions represent one of the largest uncertainties in projections of future biodiversity change.

}, keywords = {article, articles, biodiversity, global, journal, journals}, doi = {10.1126/science.287.5459.1770 }, url = {files/bibliography/JRN00301.pdf}, author = {O. E. Sala and L. Huenneke} } @article {51170, title = {Geographic patterns of simulated establishment of two Bouteloua species: Implications for distributions of dominants and ecotones}, journal = {Journal of Vegetation Science}, volume = {10}, year = {1999}, month = {1999}, pages = {343-356}, abstract = {

Our overall objective was to use a soil water model to predict spatial patterns in germination and establishment of two important perennial C4-bunchgrasses across the North American shortgrass steppe and desert grassland regions. We also predicted changes in establishment patterns under climate change scenarios. Bouteloua gracilis dominates the shortgrass steppe from northeastern Colorado to southeastern New Mexico. Bouteloua eriopoda dominates desert grasslands in central and southern New Mexico. Germination and establishment for each species were predicted at 16 sites along the gradient using a daily time step, multi-layer soil water model (SOILWAT) to determine the percentage of years that temperature and soil water criteria for germination and establishment were met. Percentage of years with predicted establishment decreased from north to south for B. gracilis, but increased from north to south for B. eriopoda, comparable to observed dominance patterns. The 95 \% confidence interval around the point at which simulated establishment were equal for the two species was near the location of the shortgrass steppe-desert grassland ecotone where both species are abundant. The intersection in percentage of years with establishment for the two species was predicted to move further north when climate was scaled using three Global Circulation Models (GCMs), indicating a possible northward expansion of B. eriopoda. Our results suggest that recruitment by seed may be an important process in determining, at least in part, the geographic distribution of these two species. Changes in climate that affect establishment constraints could result in shifts of species dominance that may or may not be accompanied by changes in species composition.

}, keywords = {Bouteloua eriopoda, Bouteloua gracilis, Chihuahuan Desert grassland, climate change, Geographic distribution, shortgrass steppe, simulation model}, doi = {10.2307/3237063}, url = {/files/bibliography/672.pdf}, author = {Minnick, T.J. and D.P. Coffin} } @article {51263, title = {Growth and root NO3- and PO4- uptake capacity of three desert species in response to atmospheric CO2 enrichment}, journal = {Austrialian Journal of Plant Physiology}, volume = {24}, year = {1997}, note = {//?//LTER III//}, month = {1997}, pages = {353-358}, abstract = {

In a phytotron experiment, we examined growth and rates of NO-3 and PO3-4 uptake in seedlings of two desert C3 shrubs (Larrea tridentata and Prosopis glandulosa) and a desert C4 perennial grass (Bouteloua eriopoda) grown under CO2 partial pressures of 35 or 70 Pa. Plants were grown in soil but uptake studies were conducted on roots of intact seedlings placed in nutrient solutions containing both NO-3 and PO3-4. Elevated CO2 increased total biomass by 69 and 55\% in Larrea and Prosopis seedlings and by 25\% in Bouteloua. NO-3 and PO3-4 uptake rates were more than doubled in Bouteloua at high compared to ambient CO2. In contrast, CO2 enrichment inhibited root NO-3 uptake capacity in Larrea by about 55\% without a significant effect on PO3-4 absorption rate; rates of NO-3 and PO3-4 and uptake in Prosopis were insensitive to CO2 treatment. Elevated CO2 enhanced the proportion of biomass allocated to the fine roots in Bouteloua but markedly reduced this fraction in Larrea and Prosopis. Foliar N concentration of both shrubs decreased in response to elevated CO2, but was unaffected in Bouteloua. We suggest that compensatory changes in root size and activity are critical in determining interspecies variation in plant nutrient relations under high CO2.

}, keywords = {article, articles, carbon dioxide enrichment, journal, journals, nitrogen, plant uptake, phosphorus, plant uptake, plant, carbon dioxide, plant, nutrient uptake}, doi = {10.1071/PP96109 }, url = {files/bibliography/JRN00240.pdf}, author = {H. BassiriRad and J. F. Reynolds and R. A. Virginia and Burnelle, M. H.} } @article {51268, title = {GePSI: A generic plant simulator based on object-oriented principles}, journal = {Ecological Modelling}, volume = {94}, year = {1997}, note = {//?//LTER III//}, month = {1997}, pages = {53-66}, abstract = {

The Generic Plant Simulator (GePSi) is a physiologically-based model that combines modules for canopy, root environment, water relations, and potential growth to generate whole-plant carbon, nitrogen, and water balances. The version presented here is coded in the object-oriented programming (OOP) language, C + +, to enhance the implementation of modularity. In the aboveground aerial environment, the Weather module defines the weather conditions above a canopy, and Micro Weather defines the vertical profiles of micro-meterological variables in a canopy. The belowground soil environment contains the SoilProperty modules, which define vertical profiles of physical and chemical variables in a soil column. The {\textquoteleft}part-of{\textquoteright} hierarchy in GePSi follows the structure of a real plant: the Plant module calls canopy and root system modules; the Canopy module, in turn, calls leaf, stem and fruit modules; and the RootSystem module calls coarse and fine root modules, etc. Our long-term goal is for GePSi to serve as a template for building a plant growth simulator by simply selecting appropriate modules for the question being asked. We are building a suite of plant modules (and their interfaces) based on general principles that are fundamentally similar for different kinds of plants. This includes photosynthesis, growth, nutrient and carbon allocation, water uptake, etc. These modules can be parameterized for specific species, related groups of species, life-forms, or broader groups depending on how variable the processes are across the groupings and the amount of unexplained variability that is acceptable for the question being investigated. Our modular-based approach has numerous advantages, including improving the understanding of the model, reducing duplication of effort, and facilitating the adaptation of the model for different sites and ecosystems.

}, keywords = {article, articles, journal, journals, model, GePSI, model, plant, plant, model}, doi = {10.1016/S0304-3800(96)01928-X}, url = {files/bibliography/JRN00239.pdf}, author = {J. Chen and J. F. Reynolds} } @conference {51294, title = {Geomorphic-vegetation relationships in the Jornada Basin, southern New Mexico}, booktitle = {International Symposium and Workshop Combating Desertification: Connecting Science with Community Action}, year = {1997}, month = {May 12-16, 1997}, pages = {Abstract 20}, address = {Tucson, AZ}, abstract = {The southern portion of the Jornada Basin is the locale of the Jomada Experimental Range and Jomada LTER site. This area is bound to the west by the Rio Grande Valley and to the east by the San Andres Mountains. The western half of the basin is the relic floodplain of the ancestral Rio Grande. The eastern half consists of a fan piedmont and exposed bedrock of the San Andres Mountains. Both the relic floodplain and the fan piedmont have been extensively modified by natural and human-induced wind erosion. Soil patterns in this setting are diverse. The age of soils ranges between 0.74 to 1.6 million years in the relic floodplain, based on Ar/Ar dating, to sediments currently being deposited by wind and arroyos. Ancient soils have massive indurated petrocalcic horizons in contrast to young soils that exhibit little difference between their surface and subsoil horizons. //Vegetation patterns are also diverse, ranging from communities dominated by single species (e.g., mesquite, creosotebush, or tarbush) to communities with a mosaic of highly diverse assemblages. In some cases vegetation patterns are highly correlated to geomorphic units. For example, mesquite is the dominant species in coppice dune terrain, creosotebush is the dominant species on some gravelly alluvial fans, and tobosa grass is the dominant species on some clayey playas. Vegetation records dating back to the mid-1800s, however, reveal a proliferation of shrubs and a decline of grasses across a variety of geomorphic units. // Several geomorphic variables, especially those involving soils and topography, influence the ability of vegetation to resist changes driven by environmental stresses. Important soil variables include particle-size distribution, available water capacity, shrink-swell properties, organic matter, microbial populations, fertility, and other soil chemical properties such as cation exchange capacity and pH. Topographic variables include aspect, runoff, and run-in characteristics that affect the distribution of soil moisture. Although the interactions of these variables are complex, some of the greatest vegetation change during the last 150 years was experienced by geomorphic units composed of sandy soils susceptible to wind erosion and by coarse shallow soils with low moisture capacities.}, author = {Curtis H. Monger and L. Huenneke and Kris Havstad} } @article {51460, title = {Grazing behavior of free-ranging beef cows to initial and prolonged exposure to fluctuating thermal environments}, journal = {Applied Animal Behavior Science}, volume = {39}, year = {1994}, note = {Reprinted with permission from Elsevier, {\textcopyright} 1994. http://www.sciencedirect.com/science/journal/01681591}, month = {1994}, pages = {103-113}, abstract = {

Effects of initial and prolonged exposure to cold ambient temperatures on the behaviors of free-ranging beef cows were examined over a fall and winter season. Mean daily temperature (MDT) and short-term thermal stress (STTS) were used to express thermal stressors. Short-term thermal stress was defined as the deviation of the current day{\textquoteright}s mean temperature from a running mean temperature of previous days (an acclimation period). Twenty different acclimation periods (calculated using temperatures from the previous 1{\textendash}20 days) were used to express 20 different acclimation lengths for determining STTS. Daily grazing time and forage intake were estimated for 15, 6-year-old gestating cows during January and February (winter trial), and for 12 of these cows during October and November (fall trial). In the winter, daily grazing time increased with increased ambient temperature and decreased with increased thermal stress (P\<0.10). Observed fluctuations in winter daily grazing time in relation to thermal stress were less than 84 min day-1. Daily grazing time was lower in the fall than winter. Cattle acclimated more quickly to STTS in the winter than in the fall. However, forage intake was consistent during both seasons and unresponsive to thermal stress. The thermal environment in these northern latitudes appeared to be only a minor influence upon grazing behaviors. It is likely that forage quality and availability, and accessibility of sites with moderate microclimates are more important environmental features effecting daily intake and total grazing time.

}, keywords = {cattle, feeding, grazing, Thermoregulatory behavior}, doi = {10.1016/0168-1591(94)90130-9}, url = {/files/bibliography/431.pdf}, author = {Prescott, M. and Kris Havstad and K. M. Olson-Rutz and E.L. Ayers and M.K. Petersen} } @mastersthesis {51484, title = {Grazing influences on watering point vegetation in the Chihuahuan desert}, year = {1993}, note = {//??//NONE//}, month = {1993}, pages = {62}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, keywords = {cattle grazing, watering point vegetation, cattle, management, watering point vegetation, dissertation, dissertations, theses, thesis}, author = {Fusco, Michael J.} } @article {51547, title = {A global budget for atmospheric NH3}, journal = {Biogeochemistry}, volume = {15}, year = {1992}, note = {//NMSU, USDA//LTER II//Listed in LTER3 proposal as citing LTER2 support//}, month = {1992}, pages = {191-211}, abstract = {

We provide an assessment of the global sources of NH3 in the atmosphere, which indicates an annual flux of about 75 Tg of N as NH3. The emissions from land are dominated by the release of NH3 during the hydrolysis of urea from the urine of domestic animals (32 TgN/yr) and by emanations from soils in unmanaged ecosystems (10 TgN/yr) and from fertilized agricultural soils (9 TgN/yr). Emissions from the sea surface may approach 13 TgN/yr. The total annual source of NH3 is in reasonable agreement with estimates of global NH4+ deposition from the atmosphere, the major fate of atmospheric NH3. As an alkaline atmospheric species, NH3 emitted to the atmosphere each year can neutralize only about 32\% of the annual production of H+ in the atmosphere from natural and anthropogenic sources.

}, keywords = {acid deposition, ammonia volatilization, article, articles, cattle,ammonia, climate,ammonia volatilization, fertilizer,ammonia, fire,ammonia, journal, journals, nitrogen cycling, nutrient cycling, ammonia, nutrient cycling, nitrogen, soil nitrogen, urea}, url = {files/bibliography/JRN00148.pdf}, author = {W. H. Schlesinger and Anne E. Hartley} } @article {51564, title = {Grazing behavior of rangeland beef cattle differing in biological type}, journal = {Journal of Animal Science}, volume = {69}, year = {1991}, month = {1991}, pages = {1435-1442}, abstract = {

Grazing behavior exhibited by different biological types (breed groups) of lactating beef cows was evaluated during the summers of 1985 (Trial 1) and 1986 (Trial 2). Animals grazed native Montana foothill grassland. In Trial 1, breed groups consisted of Hereford (BM, 50\% Angus-50\% Hereford (AH), 50\% Simmental-50\% Hereford (SH), and 75\% Simmental-25\% Hereford (3S1H) with six cows per breed group. Daily grazing hours were 11.8 {\textpm} .2, 12.3 {\textpm} .2, 11.6 {\textpm} .2, and 11.6 {\textpm} .5 h/d for HH, AH, SH, and 3S1H, respectively. There was a tendency for AH cows to graze longer than HH and SH cows (P = .10). Bite rates were 52.7 {\textpm} 1.5, 56.2 {\textpm} 1.5, 53.2 {\textpm} 1.4, and 59.0 {\textpm} 1.6 bites/min for HH, AH, SH, and 3S1H, respectively. The AH and 3S1H cows had higher bite rates (P \< .05) than the HH and SH cows. Means for distance traveled were 3.1 {\textpm} .2, 3.4 {\textpm} .2, 4.0 {\textpm} .2, and 2.8 {\textpm} .2 km/d for HH, AH, SH and 3S1H, respectively. The SH cows tended to travel farther (P \< .10) than cows of other breed groups. The AH traveled farther than the 3S1H but did not differ from the HH. In Trial 2, breed groups were Hereford (HH), Tarentaise-Hereford (TH), Tarentaise-Simmental-Hereford (T(SH)), and Charolais-Simmental-Hereford(C(SH)); each group included six lactating cows. Means for bite rate were 56.9 {\textpm} 1.1, 58.7 {\textpm} 1.1, 60.9 {\textpm} 1.0, and 59.0 {\textpm} 1.1 bites/min for HH, TH, T(SH), and C(SH), respectively. The T(SH) cows had a higher bite rate than the RH cows (P \< .10), but bite rates did not differ between T(SH) and TH or C(SH) cows. Breed group means were not different (P \> .10) for grazing time and distance traveled. Thus, bite rate was the only behavioral expression that was consistently different among breed groups and may be a response that allows different biological types to achieve different levels of intake.

}, keywords = {beef cattle, breeds, grazing behavior, groups, rangelands}, url = {/files/bibliography/708.pdf}, author = {Funston, R.N. and Kress, D.D. and Kris Havstad and D. E. Doornbos} } @inbook {51569, title = {Grazing Management}, booktitle = {Semiarid Lands and Deserts: Soil Resource and Reclamation}, year = {1991}, month = {1991}, pages = {361-385}, publisher = {Marcel Dekker, Inc.}, organization = {Marcel Dekker, Inc.}, address = {New York, NY}, abstract = {A major use of semiarid and arid lands ("rangelands" in this chapter) is grazing or browsing by livestock and wild herbivores. Rangelands also provide habitat for wildlife, recreational opportunities, water, and aesthetic values. Animal production on rangelands reduces the requirements for nonrenewable fossil fuels and utilizes resources not readily usable by other means. Semiarid and arid rangelands are often fragile and subject to accelerated soil erosion if not managed appropriately. If rangelands are mismanaged so that plants fail to provide sufficient soil cover, the composition of the plant community changes, resulting in reduced productivity and increased erosion. Continued abuse of the rangeland system can result in severe soil degradation. This does not imply that proper grazing is destructive; some plants produce more biomass with moderate livestock grazing than with protection from livestock grazing. Some native plant communities evolved with grazing use by native animals, whereas other communities evolved with little or no utilization by herbivores. However, native plant communities are not always the most productive under intensive animal grazing (Herbel, 1982). Revegetation with introduced or improved plant species may dramatically increase the productivity of rangelands (Herbel, 1983). Grazing of livestock is controlled to some degree by range managers and pastoralists around the world. However, many important environmental factors are beyond control of the manager, but these factors need to be considered in planning grazing management and future research on the subject.}, keywords = {environmental factors, increased erosion, livestock, management, rangelands, reduced productivity}, url = {/files/bibliography/370.pdf}, author = {C.H. Herbel and Pieper, Rex D.}, editor = {Skujins, J.} } @conference {51580, title = {GIS applications in rangeland research on the Jornada Experimental Range}, booktitle = {Annual Meeting, Society for Range Management}, year = {1991}, month = {1991}, pages = {No. P64}, abstract = {The Jornada Experimental Range occupies 193,000 acres of semiarid land in south-central New Mexico and has been operated continuously as a research facility since 1915. The long-term database includes forage biomass, stocking, precipitation from up to 54 gauges, and brush control measures. A geographic information system (GIS) has been used to organize, document, and provide analytical tools for this database. Basic map coverages, including roads, pastures, stock water, rain gauges, topography, soils, vegetation, and boundaries, have been converted to digital form. The GIS combines ready access to tabular data through attribute tables with a unique capability for visualization and analysis through map overlays. We have used it to analyze rainfall distributions, measure wildlife home ranges, and record aerial coverages of herbicide application. At present, it is being used to provide overlay maps for satellite imagery in support of remote sensing research. In that work, topography overlays aid in registration of the imagery and vegetation overlays are used to verify spectral image classifications and identify components of each classification. Results are expected to improve remote sensing techniques for rapid monitoring of semiarid rangeland conditions.}, keywords = {GIS, Jornada Experimental Range, long-term database, monitoring rangeland conditions, rangeland research, remote sensing techniques}, author = {Mason, J.B. and Gibbens, Robert P. and Kris Havstad} } @article {51585, title = {A general model of litter decomposition in the northern Chihuahuan Desert}, journal = {Ecological Modelling}, volume = {56}, year = {1991}, note = {//NMSU//LTER II//Listed in LTER3 proposal as citing LTER2 support//}, month = {1991}, pages = {197-219}, abstract = {

We developed a general, synthetic model to examine the interactions between buried litter, decomposer microorganisms, and C and N pools in this ecosystem. Our goal is to explore the mechanisms underlying observed patterns of decomposition in arid systems using a modeling approach that balances simplicity with enough detail to suggest the reasons for system behavior.... This study indicates that the pattern of microbial activities, accounting for the decomposition of buried materials in the absence of termites, is primarily determined by climatic conditions.

}, keywords = {article, articles, decomposition,litter model, journal, journals, litter decomposition, SEE , model,litter decomposition}, doi = {10.1016/0304-3800(91)90200-K}, url = {files/bibliography/JRN00134.pdf}, author = {Daryl L. Moorhead and J. F. Reynolds} } @article {51593, title = {Ground-dwelling arthropods of the Rio Puerco Watershed, New Mexico}, journal = {Arid Soil Research and Rehabilitation}, volume = {5}, year = {1991}, note = {//OTHER//NONE//}, month = {1991}, pages = {147-153}, abstract = {

One of the most important components of a terrestrial ecosystem is the ground-dwelling arthropods, which play a functional role as general detritivores and predators. Because of their sensitivity to rangeland deterioration, a study on the abundance of the ground-dwelling arthropods was undertaken in four different habitats of the Rio Puerco Watershed in New Mexico. Thirty-two traps (768 trap nights) were place in each of four habitats: grama grassland, sagebrush, shrubland, juniper grassland, and pine woodland. There were more general of ants in the juniper grassland habitat than in the other habitats. Fieldcrickets, Gryllus sp., were most abundant in the grama grassland and entomobryid collembolans were most abundant in juniper grassland and pine woodland habitats. Despite difference in species composition, the ground-dwelling arthropod fauna was dominated by detrivouous forms in every habitat.

}, keywords = {arthropod, ground-dwelling, article, articles, journal, journals}, doi = {10.1080/15324989109381274}, url = {files/bibliography/91-ArdSlReschandRehab-Whitford.pdf}, author = {Yosef Steinberger and Earl F. Aldon and Walter G. Whitford} } @article {51595, title = {Grazing behavior of Angora goats confined to a semi-desert mesquite brush dominated rangeland}, journal = {Proceedings. Western Section, American Society of Animal Science}, volume = {42}, year = {1991}, note = {//??//NONE//}, month = {1991}, pages = {177-179}, keywords = {article, articles, behavior,goats, brush control,goats, brush control,Prosopis, goat,behavior, goat,brush control, journal, journals, Prosopis,brush control}, author = {Tejada-Velez, E. H. and H.E. Kiesling and Reldon F. Beck and Southward, G.M.} } @inbook {51616, title = {Grazing Management, Part I}, booktitle = {The Improvement of Tropical \& Subtropical Rangelands}, year = {1990}, month = {1990}, pages = {116-138}, publisher = {National Academies Press}, organization = {National Academies Press}, address = {Washington, D.C.}, author = {C.H. Herbel}, editor = {National Research Council} } @conference {51638, title = {Gas exchange and water relations of the polyploid shrub Atriplex canescens growing in the northern Chihuahuan Desert}, booktitle = {43rd Annual Meeting, Society for Range Management}, year = {1990}, month = {1990}, pages = {Abstract 51}, address = {Reno, NV}, author = {R.S. Senock and J.R. Barrow and Gibbens, Robert P. and C.H. Herbel} } @article {51662, title = {Growth patterns of range beef calves over discrete preweaning intervals}, journal = {Canadian Journal of Animal Science}, volume = {69}, year = {1989}, month = {1989}, pages = {865-869}, abstract = {

Suckling range beef calf production demonstrates periodicity despite consistency of management. Performance of calves within 33- to 50-d intervals from birth to weaning over nine seasons demonstrated maximum interval growth of approximately 1 kg d-1, but average seasonal growth rates varied from 0.79 to 0.99 kg d-1.Maximizing available forages for the final 33 d preweaning could minimize seasonal variations in calf production.

}, keywords = {Calf production, live weight gain, rangelands}, doi = {10.4141/cjas89-099}, url = {/files/bibliography/701.pdf}, author = {Kris Havstad and McInerney, M.J. and Church, S.B.} } @proceedings {51663, title = {Grazing systems on arid and semiarid rangelands}, year = {1989}, month = {1989}, pages = {79-80}, address = {San Francisco, CA}, author = {C.H. Herbel} } @proceedings {51683, title = {Grazing behavior responses of free-ranging beef cows to fluctuating thermal environments}, volume = {40}, year = {1989}, month = {1989}, pages = {458-460}, abstract = {

Effects of initial and prolonged exposure to cold ambient temperatures on the behaviors of free-ranging beef cows were examined over a fall and winter season. Mean daily temperature (MDT) and short-term thermal stress (STTS) were used to express thermal stressors. Short-term thermal stress was defined as the deviation of the current day{\textquoteright}s mean temperature from a running mean temperature of previous days (an acclimation period). Twenty different acclimation periods (calculated using temperatures from the previous 1{\textendash}20 days) were used to express 20 different acclimation lengths for determining STTS. Daily grazing time and forage intake were estimated for 15, 6-year-old gestating cows during January and February (winter trial), and for 12 of these cows during October and November (fall trial). In the winter, daily grazing time increased with increased ambient temperature and decreased with increased thermal stress (P\<0.10). Observed fluctuations in winter daily grazing time in relation to thermal stress were less than 84 min day-1. Daily grazing time was lower in the fall than winter. Cattle acclimated more quickly to STTS in the winter than in the fall. However, forage intake was consistent during both seasons and unresponsive to thermal stress. The thermal environment in these northern latitudes appeared to be only a minor influence upon grazing behaviors. It is likely that forage quality and availability, and accessibility of sites with moderate microclimates are more important environmental features effecting daily intake and total grazing time.

}, url = {/files/bibliography/702.pdf}, author = {Prescott, M. and K. M. Olson-Rutz and Kris Havstad and E.L. Ayers and M.K. Petersen} } @article {51741, title = {Growth of Gutierrezia sarothrae seedlings in the field}, journal = {Journal of Range Management}, volume = {41}, number = {1}, year = {1988}, note = {//NMSU//NONE//}, month = {1988}, pages = {92-93}, abstract = {Broom snakeweed (Gutierrezia sarothrae [Pursh] Britt. and Rusby) has increased in density and distribution on many southwestern ranges. The objective of this study was to determine root and shoot development of snakeweed seedlings as an aid in understanding the establishment of the species. Broom snakeweed seedlings were excavated from the field from March through September at approximately monthly intervals to determine biomass of roots and shoots. Root and shoot biomass growth was comparable from March to July, but shoot growth exceeded that by roots of the rest of the growing season. Root:shoot ratios were below 0.6 for the entire growing season, suggesting that rapid root development is not the primary mechanism for colonizing disturbed areas.}, keywords = {article, articles, Gutierrezia, root:shoot ratios, journal, journals, seedling,Gutierrezia}, author = {Abdelgader Osman and Pieper, Rex D.} } @proceedings {51790, title = {Guidebook to the Socorro Area, New Mexico}, year = {1987}, note = {//OTHER//NONE//}, month = {October 19-22, 1}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, address = {Socorro, New Mexico}, abstract = {

The roadlogs in this guidebook were written primarily for the field trips of the 24th annual meeting of the Clay Minerals Society and the 36th annual Clay Minerals Conference held in Socorro, New Mexico, October 19-22, 1987.... This guidebook is organized into three parts: 1) an introduction to the Socorro area; 2) roadlogs, and 3) short papers that supplement the field trips.

}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, geomorphology, proceeding, proceedings}, author = {McLemore, Virginia T.}, editor = {Bowie, Mark R.} } @article {51795, title = {Geology of east half of Las Cruces and northeast of El Paso 1{\textordmasculine} x 2{\textordmasculine} sheets}, year = {1987}, note = {//OTHER//ProCite field[33]: 57}, month = {1987}, publisher = {New Mexico Bureau of Mines \& Mineral Resources}, keywords = {geology, map, map, geology}, author = {W. R. Seager and J. Hawley and Frank E. Kottlowski and Kelley, S. A.} } @proceedings {51944, title = {Grass and forb production on sprayed and nonsprayed mesquite (Prosopis glandulosa Torr.) dunes and interdunes in south-central New Mexico}, year = {1983}, month = {1983}, pages = {437-440}, address = {Lexington, KY}, abstract = {Production of grasses and forbs was measured for 4 years beginning in 1976 and following aerial application of 2,4,5-T to 3,634 ha of mesquite (Prosopis glandulosa Torr.) dunelands on the Jornada Experimental Range in south-central New Mexico. Plant production was also measured on a 3,318-ha control area. The mesquite dunelands arc representative of large areas in the southwestern USA where mesquite has invaded former desert grasslands. Objectives of the study were to determine forage increases attributable to reduced mesquite competition and to evaluate the relationships between production and precipitation. Both sprayed and control areas were grazed by cattle. Temporary exclosures were used to exclude cattle from three sampling sites on the sprayed and control areas each year. The sampling sites were all on sandy ranges with relatively deep soils (>50 cm to caliche layer). A dune-centered sampling system permitted the determination of differences in production on dune and interdune areas. The mesquite dunes, occupying 28\% of the land surface, produced more annual forbs and fewer perennial grasses than the interdune areas. Stem kill of mesquite averaged 56\% at sampling sites on the sprayed area. End-of-season harvests were used to compare treatments.}, keywords = {dunelands, forbs, grasses, mesquite, New Mexico, nonsprayed, Prosopis glandulosa Torr., sprayed}, url = {/files/bibliography/230.pdf}, author = {Gibbens, Robert P.} } @conference {51945, title = {Grassland forb production during a five-year period on sprayed and nonsprayed mesquite dunelands in Southern New Mexico}, booktitle = {36th Annual Meeting, Society for Range Management}, year = {1983}, month = {1983}, pages = {No. 9}, keywords = {dunelands, forb production, grassland, mesquite, nonsprayed, sprayed}, author = {Gibbens, Robert P.} } @proceedings {51972, title = {Gamma-irradiated sewage solids as feed for ruminants}, year = {1983}, month = {1983}, pages = {575-576}, address = {Tokyo, Japan}, abstract = {Dried solids from primary sludge in domestic municipal sewage were disinfected by gamma-irradiation and used effectively as supplemental feed for cattle and sheep in practical, long-term studies of reproductive performance with negligible evidence of toxicity and heavy metals accumulation. Sewage products contained about 20\% crude protein that was digested and retained, as well as protein in cottonseed meal. Increased usage of novel resources as feed for animals seems vital toward meeting human food needs in the future. Sewage represents a vast resource of nutrients that could be used in animal feed when technology based on science is applied to assure product efficacy and safety. This report summarizes main results from a 7-year research program that assessed nutritive value of dried, gamma-irradiated solids from primary sewage sludge and the risks of toxicants in long-term trials with cattle and sheep.}, keywords = {feed, gamma-irradiated, ruminants, sewage solids}, url = {/files/bibliography/248.pdf}, author = {Geoffrey Smith and Hallford, D.M. and C.H. Herbel and H.E. Kiesling and Ray, E.E.} } @article {52008, title = {Grazing management on rangelands}, journal = {Journal of Soil and Water Conservation}, volume = {37}, year = {1982}, month = {1982}, pages = {77-79}, abstract = {

RANGELANDS are a major life-support system for mankind. They provide forage for livestock and wildlife, habitat for wildlife, recreational opportunities, water, and aesthetic values. Today{\textquoteright}s growing numbers of people are putting more and more demands on rangeland productivity. Forage-based livestock production reduces grain requirements, conserves energy, and uses resources not readily usable by other means. To meet forage-fed livestock needs and provide the other products and services that people expect from rangelands, these lands must be managed wisely. If rangelands are mismanaged to the extent that plant cover fails to provide sufficient soil cover, the species composition of the plant communities changes, reducing productivity and soil protection. Continued abuse can result in severe soil erosion. This does not imply that proper grazing is destructive. Some native plant communities evolved over thousands of years with grazing use by native animals. But native plant communities are not always the most productive under intensive livestock grazing. Production can be increased on some sites with the use of improved forage plants.

}, keywords = {grazing management, rangelands}, url = {/files/bibliography/219.pdf}, author = {C.H. Herbel} } @proceedings {52018, title = {Gamma-irradiated products from sewage as supplemental feed for ruminants}, volume = {41}, year = {1982}, month = {1982}, pages = {33-34}, author = {Geoffrey Smith and Hallford, D.M. and C.H. Herbel and H.E. Kiesling and Ray, E.E. and Sivinski, J. S.} } @proceedings {52032, title = {Grass and forb production on sprayed and nonsprayed mesquite (Prosopis glandulosa Torr.) dunelands in south-central New Mexico}, year = {1981}, month = {1981}, pages = {222}, address = {Lexington, KY}, abstract = {

Production of grasses and forbs was measured for 4 years beginning in 1976 and following aerial application of 2,4,5-T to 3,634 ha of mesquite (Prosopis glandulosa Torr.) dunelands on the Jornada Experimental Range in south-central New Mexico. Plant production was also measured on a 3,318-ha control area. The mesquite dunelands arc representative of large areas in the southwestern USA where mesquite has invaded former desert grasslands. Objectives of the study were to determine forage increases attributable to reduced mesquite competition and to evaluate the relationships between production and precipitation. Both sprayed and control areas were grazed by cattle. Temporary exclosures were used to exclude cattle from three sampling sites on the sprayed and control areas each year. The sampling sites were all on sandy ranges with relatively deep soils (\>50 cm to caliche layer). A dune-centered sampling system permitted the determination of differences in production on dune and interdune areas. The mesquite dunes, occupying 28\% of the land surface, produced more annual forbs and fewer perennial grasses than the interdune areas. Stem kill of mesquite averaged 56\% at sampling sites on the sprayed area. End-of-season harvests were used to compare treatments.

}, keywords = {dunelands, forbs, grasses, mesquite, New Mexico, nonsprayed, Prosopis glandulosa Torr., sprayed}, url = {/files/bibliography/194.pdf}, author = {Gibbens, Robert P.} } @proceedings {52075, title = {Grasslands, systems analysis and man}, year = {1980}, note = {//??//??//}, month = {1980}, publisher = {Cambridge Press}, keywords = {abstract, abstracts, climate,ecological climatology, climate,phytogeographic, conference, conference proceedings, conferences, proceeding, proceedings}, author = {Breymeyer, A. I.}, editor = {VanDyne, G. M. (ed.)} } @mastersthesis {52086, title = {Grazing behavior and diet composition of cattle on continuously and seasonally grazed semiarid ranges}, year = {1980}, note = {//??//NONE//}, month = {1980}, pages = {50}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, keywords = {cattle grazing, management, cattle grazing,behavior, cattle,diet, dissertation, dissertations, theses, thesis}, author = {Heithold, Donavon William} } @article {52094, title = {Growth patterns and biomass relations of Xanthocephalum sarothrae (Pursh) Shinners on sandy soils in southern New Mexico}, journal = {Journal of Range Management}, volume = {33}, number = {5}, year = {1980}, note = {//NMSU//NONE//}, month = {1980}, pages = {394-397}, abstract = {Growth patterns of broom snakeweed were studied on three areas of sandy range sites in southern New Mexico by measuring plant canopy biweekly during the growing season and calculating canopy volume. Canopy volume increased during the summer of 1977 on all three study areas. In 1978, canopy volume declined throughout much of the growing season because effective rainfall came late in the season. More than 60\% of the canopy biomass was contributed by brown stems and leaves, about 30\% by green leaves and stems, and less than 10\% by inflorescence on most dates. Coefficients of determination relating canopy volume to canopy biomass were less than 0.70. Growth forms and patterns were quite variable among the populations studied.}, keywords = {article, articles, biomass,Xanthocephalum, journal, journals, plant productivity,Xanthocephalum, Xanthocephalum, biomass estimates, Xanthocephalum,growth patterns, Xanthocephalum,productivity}, author = {Samu Nadabo and Pieper, Rex D. and Reldon F. Beck} } @mastersthesis {52120, title = {Growth and development patterns of black grama in southern New Mexico}, year = {1979}, note = {//NMSU//NONE//}, month = {1979}, pages = {92}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = { The objectives of this study were to 1) provide an accurate description of growth and development of black grama; 2) determine reproductive potential of all stem types within this species; and 3) distinguish the most important factors influencing new plant establishment by vegetative means. Three years of black grama shoot production were classified according to their position of growth during a two-year period. Horizontal shoots, which have generally been referred to as stolons included shoots growing along or near the soil surface. Vertical shoots, generally classified as flower stalks or floral culms, included shoots in a position +/- 25 degrees from the vertical; while angular shoots included those shoots which occur throughout the plant at approximately a 45 degree angle and have been referred to as either stolons or floral culms. Shoots were permanently marked with non-restricting color rings and changes in development and position were evaluated over a two-year period. No apparent morphological differences were noted between the three categories of shoots. All shoots followed the general phenological pattern of vegetative growth, floral development, quiescence and senescence. The period of time shoots remained in these phases appeared to depend upon prevailing conditions of precipitation, temperature and day length. Amounts of axillary branching, which are the potential for vegetative reproduction in black grama, were nearly equal for all categories. Of the three categories of shoot position, proportions of axillary branches which became rooted during the study period were greatest for the horizontal category. Angular shoots rooted about 30\% of the total, while vertical shoots only rarely contributed to vegetative reproduction. Differences in proportion of positional change within the three categories appeared responsible for the observed difference in rooted axillary branching. These differences were also related to the amount of time axillary branches were in position to take advantage of the relatively short periods during the growing season when conditions were favorable for rooting. Comparison of grazed and ungrazed plants suggests that the chances for establishment of axillary branches on shoots in the horizontal position are not severely impaired under a moderate grazing regime, although a greater percentage were broken by trampling. Angular shoots were less susceptible to trampling, but about 30\% were consumed during the 1978 growing season. Practically all vertical shoots were removed under moderate grazing. Hoof action may improve the chances for establishment of rooted axillary branches by covering their crown bases with loose soil and providing more favorable rooting conditions through breakup of the hard-surfaced soil crust.}, keywords = {Bouteloua, phenology, cattle grazing, Bouteloua, dissertation, dissertations, grass, Bouteloua, grassland, Bouteloua, phenology, phenology, also SEE , phenology,Bouteloua, theses, thesis}, author = {Kirk Gadzia} } @proceedings {52143, title = {A grazing system for semiarid lands}, volume = {Vol. 1}, year = {1978}, note = {//NMSU//NONE//ProCite field[6]: In}, month = {1978}, publisher = {Society of Range Management}, abstract = {A seasonal suitability grazing system was started on semiarid grassland in 1967. Ten years of data have not shown it to be superior to yearlong grazing with which it was compared. Livestock performance was similar on the two systems. Drought and conservative stocking rates were primarily responsible for the lack of differences between the systems. Flexibility, a primary component of the seasonal suitability system, allows for specific management of perennial grasses. Sampling of vegetaion was not intensive enough to detect the observable improvement on the seasonal suitability pastures.}, keywords = {abstract, abstracts, cattle grazing,management, conference, conference proceedings, conferences, grass, Aristida, grass, Bouteloua, grass, Erioneuron, grass, Sporobolus, grassland, grazing system, grazing system, management,grazing system, proceeding, proceedings, shrub, Xanthocephalum, snakeweed, SEE Xanthocephalum, Gutierrezia}, author = {Reldon F. Beck}, editor = {D. H. (ed.) Hyder} } @mastersthesis {52161, title = {Growth patterns of broom snakeweed (Xanthocephalum sarothrae (Pursh) Shinners) in southern New Mexico}, year = {1978}, note = {//NMSU//NONE//}, month = {1978}, pages = {67}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {A study was conducted to evaluate growth characteristics of broom snakeweed plants at three locations on the New Mexico State University Ranch, located about 32 km north of Las Cruces. Twenty individual plants were marked with wooden stakes at each location. Height and average diameter of each plant were measured biweekly during the growing season in 1977 and 1978. Measurements of the same attributes were taken biweekly on ten additional plants at each location in 1977, These plants were harvested and hand-separated into green and brown leaves and branches and flower parts, oven-dried and weighed. Regression analysis, used to predict biomass of snakeweed and component parts from height, diameter and volume measurements, indicated that these variables accounted for much of the variations in the models obtained. Further analysis of variance generally showed that differences among sites and dates were significant (P<.05), indicating that there was considerable variation in growth form among plants within and between growing seasons. Observations also suggested that adequate and timely precipitation, especially in July and August, significantly influenced the growth form of snakeweed plants during both growing seasons.}, keywords = {biomass,Xanthocephalum, dissertation, dissertations, plant,snakeweed, plant,Xanthocephalum,plant,Gutierrezia, productivity,Xanthocephalum, snakeweed, SEE , theses, thesis, Xanthocephalum, Xanthocephalum, biomass estimates, Xanthocephalum, growth patterns}, author = {Samu Nadabo} } @mastersthesis {52208, title = {Growth patterns of Hereford and Brangus cows under two different environments}, year = {1976}, note = {//NMSU//NONE//}, month = {1976}, pages = {70}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, keywords = {cattle, environmental factors, cattle, growth patterns, dissertation, dissertations, theses, thesis}, author = {Lopez de Torre, Guillermo} } @mastersthesis {52234, title = {Grazing effects on a desert grassland}, year = {1975}, note = {//NMSU//NONE//}, month = {1975}, pages = {37}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {Grazing effects were studied on aerial and underground phytomass, soil cover condition, and on bulk density, organic matter and texture of the soil, on the New Mexico State University Ranch near Las Cruces in August 1975. Total phytomass was not significantly different (P> 0.1) between ungrazed and grazed treatment. However, grazing did change its composition. Grasses made up 78.7 percent and 7.3 percent; forbs 21.3 percent and 92.7 percent of the total phytomass on the ungrazed and grazed areas, respectively. Fluff grass was the only grass that increased in absolute value on the grazed area. Black grama was the most affected grass, decreasing from 483.8 kg/ha on the ungrazed area to 1.6 kg/ha on the grazed area. Total forb phytomass was higher (P<0.01) on the grazed treatment than on the ungrazed treatment. Snakeweed was the most important species on the grazed area. Twoleaf senna was the only forb found on the grazed and not on the ungrazed area. There was 20 percent more bare ground and five times less plant cover on the grazed area than on the ungrazed area. Clay percent in the soil was significantly less (P<0.05) on the grazed area. Organic matter percent was significantly higher (P<0.01) on the ungrazed than on the grazed area.}, keywords = {cattle grazing, effects on plants, dissertation, dissertations, plant, grazing effects, theses, thesis}, author = {Ibarra Gil, Humberto} } @proceedings {52239, title = {Geology and ground-water resources of the Las Cruces area, New Mexico}, year = {1975}, note = {//LOCAL//NONE//}, month = {1975}, pages = {195-204}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, abstract = {This report is a brief review of the geology and ground-water resources of a 550 sq mi area surrounding Las Cruces, Dona Ana County, New Mexico. The area includes the southern and northern ends, respectively, of the Jornada del Muerto Basin and the Mesilla Bolson, which are crossed by the entrenched Mesilla Valley of the Rio Grande (Fig. 1). Mountains flanking the basin and the valley areas are the Sand Andres-Organ range on the east, and the Dona Ana Mountains to the north, and the Robledo-Picacho uplifts to the northwest (Fig. 1).}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, geology, ground-water, geomorphology, proceeding, proceedings, water, ground-water resources}, author = {King, William E. and J. Hawley} } @mastersthesis {52247, title = {The growth patterns, productivity, and phytosociology of soaptree yucca (Yucca elata Engelm)}, year = {1975}, note = {//NMSU//US-IBP//}, month = {1975}, pages = {87}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {Biomass allocated to reproductive structures in Yucca elata was compared to net leaf growth over a five year period (1971-1975) on two sites in southern New Mexico.... The phytosociological characteristics of Yucca elata were examined on the New Mexico State University Jornada Experimental Ranch. Yucca elata appears to reach its best development in the desert grassland association, where it occurs in large, evenly spaced clumps. It is thought to occur only in the more mesic areas of the desert scrub formation, and is possibly a "relic" of past grassland vegetation in these areas. Yucca elata is most closely associated with Prosopis glandulosa and Xanthocephalum sarothrae throughout its range on the Jornada.}, keywords = {dissertation, dissertations, plant,soaptree yucca,Yucca, productivity,Yucca, theses, thesis, Yucca, productivity, Yucca,growth patterns, Yucca,phytosociology}, author = {Stanley D. Smith} } @article {JRN54837, title = {Gl28-A New Allele for Pigment Glands in Cotton1}, journal = {Crop Science}, volume = {14}, year = {1974}, month = {March 1974}, pages = {325-326}, chapter = {325}, abstract = {

A new gland phenotype was observed in cotton (Cossypium hirsutum L.) segregating for Gl2 and Gl3. A genetic analysis was conducted to determine the inheritance of this character. It was found that the gene responsible was allelic to Gl2. The new allele was designated Gl28. Gl28 in the homozygous condition (Gl28Gl28 gl3gl3) imparts reduced gland density in the cotyledons, as compared to Gl2 or Gl3, with apparent normal gland distribution in the stems and petioles.

}, keywords = {Allelism, Insect resistance, Seed gossypol}, url = {https://dl.sciencesocieties.org/publications/cs/pdfs/14/2/CS0140020325}, author = {J.R. Barrow and D. D. Davis} } @mastersthesis {52289, title = {The gemination responses of three semidesert grasses to temperature, moisture, and depth of planting}, year = {1974}, note = {//??//NONE//}, month = {1974}, school = {New Mexico State University}, type = {M.S. Thesis}, address = {Las Cruces, New Mexico}, keywords = {dissertation, dissertations, germination,grasses, grass,germination, theses, thesis}, author = {Zambuk, U. Y.} } @proceedings {52303, title = {Grazing systems on native range}, volume = {Publication No. 63}, year = {1973}, month = {1973}, pages = {K-1--K-19}, publisher = {Great Plains Agricuture Council}, address = {Lincoln, NE}, abstract = {This review is concerned primarily with research on grazing systems on native ranges in the ten Great Plains states. Basic information on climate and vegetation is presented so results may be disseminated and adapted as widely as possible. To keep this paper within space limitations, only studies concerned with specialized grazing systems are considered. Generally, this means that some scheme of livestock manipulation other than continuous grazing was studied. Short-term experiments generally are not considered because the author feels it takes several years for the treatments to have conclusive effects on vegetation and livestock performance. Other management strategies not considered in this paper are calving or lambing dates, levels of supplemental feeding, methods of obtaining better livestock distribution and range improvements. Studies are reviewed by major vegetation regions.}, keywords = {grazing systems, Great Plains, native ranges, vegetation regions}, url = {/files/bibliography/140.pdf}, author = {C.H. Herbel} } @proceedings {52336, title = {Geologic-geomorphic mapping to serve soil resource development}, year = {1972}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {August 6-9, 1972}, pages = {24-30}, publisher = {Soil Conservation Society of America}, address = {Hilton Hotel, Portland, Oregon}, abstract = {A better understanding of the distribution, composition, and genesis of natural features at or near the earth{\textquoteright}s surface increases man{\textquoteright}s ability to develop soil uses that are in closer harmony with the environment. Field and laboratory studies in geology and its subdiscipline, geomorphology, especially as shown on maps and cross sections, can be particularly helpful in soil resource evaluation and development.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, Desert Project, geomorphology,mapping, map,geologic-geomorphic, proceeding, proceedings, soil, resource development, soil,geologic-geomorphic map}, author = {J. Hawley} } @proceedings {52365, title = {The grassland biome: a synthesis of structure and function, 1970}, year = {1971}, note = {//USDA//US-IBP//NMSU library QH541.5 .P7 .P74//ProCite field[6]: In}, month = {September 1, 197}, pages = {317-387}, publisher = {Colorado State University}, address = {Colorado State University, Fort Collins, Colorado}, abstract = { The structures of the ecosystems of the Comprehensive Network Sites of the Grassland Biome study have been compared with reference to site constants, treatment variables, and 1970 state variables. The primary producer state variables studied included seasonal trends and time-weighted means of aboveground standing crop of primary producers by category and functional group, mulch, and belowground standing crop. Consumer variables studied included seasonal trends and time-weighted means of invertebrate density and standing crop by families and trophic levels and small mammal and bird standing crops by species and ecological groups. In addition, typical standing crops of domestic livestock were compared.}, keywords = {abstract, abstracts, Aves,grassland, biomass,grassland, conference, conference proceedings, conferences, grassland,Aves, grassland,function, grassland,invertebrate, grassland,Rodentia, grassland,structure, invertebrate,grassland, proceeding, proceedings, Rodentia,grassland}, author = {J. K. Lewis}, editor = {Norman R. French} } @proceedings {52386, title = {A guide to the mathematical modelling of an ecosystem}, year = {1970}, note = { //??//??//ProCite field[6]: In}, month = {June 19691970}, pages = {75-99}, publisher = {Colorado State University}, address = {University of New Mexico, Albuquerque}, abstract = { The following report is the joint effort of a small group working in the spring of 1969 in preparation for the workshop. Rainfall data did not arrive until late May, so the group concentrated on those features of the ecological climatolgy of the Jornada which it could consider with limited data. The report thus consists of three main parts: an analysis of the standard climatic factors that appear to limit the plants of the Jornada, an analysis of heat and moisture budgets appropriate to the cover types of the Jornada, and a preliminary estimate of the spatial and seasonal patterns of precipitation in equation form for use in a computer model. In addition to the workshop participants Hayden, Webb, Mitchell, and Bryson, the group was regularly joined by Dr. Katharina Lettau and Dr. F. Kenneth Hare whose contributions were very important.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, model,ecosystem, proceeding, proceedings}, author = {Clymer, A. B. and Bledsoe, L. J.}, editor = {R. G. Wright and G.M. Van Dyne} } @article {JRN55002, title = {Grazing Management Systems}, year = {1970}, month = {04/1970}, pages = {1-21}, institution = {New Mexico Inter-Agency Range Committee}, address = {Las Cruces}, abstract = {

Much of New Mexico{\textquoteright}s rangelands have become depleted of their natural and desired vegetative cover due to past management, drought, encroachment of undesirable plants, and other factors. These conditions or factors have seriously affected runoff, sediment, aesthetics, wildlife habitat, and forage production. Increases in undesirable plants also have caused problems in recreational and highway areas.

}, url = {files/bibliography/Herbel-02.pdf}, author = {C.H. Herbel} } @article {52417, title = {Grazing management on semidesert ranges in southern New Mexico}, year = {1969}, month = {1969}, pages = {13 }, institution = {Jornada Experimental Range Report No. 1}, abstract = {We will attempt to discuss some of the features of managing arid southern New Mexico ranges with someemphasis on benefits of various practices. Much of this research work was conducted at the Jornada Experimental Range near Las Cruces, New Mexico. The Jornada Range was established in 1912. The major emphasis of the research program has been on grazing management and range ecology. It has only been in recent years that we have also given some attention to brush control and seeding.}, keywords = {government publication, grazing management, range ecology, semidesert range}, url = {/files/bibliography/114.pdf}, author = {C.H. Herbel and Nelson, A.B.} } @article {52449, title = {Grazing distribution patterns of hereford and Santa Gertrudis cattle on a southern New Mexico range}, journal = {Journal of Range Management}, volume = {20}, number = {5}, year = {1967}, note = {Permission to post articles granted by the Society for Range Management; www.rangelands.org.}, month = {September 1, 196}, pages = {296-298}, abstract = {Actual observations for 3 years and utilization surveys for 4 years were used to determine the grazing distribution patterns of Hereford and Santa Gertrudies cattle in southern New Mexico. The grazing patterns of the two breeds were similar in the pastures studies. There was good distribution throughout the pastures which extended 3.5 miles from water. In larger pastures, Santa Gertrudis cows grazed farther from water than Hereford cows because they walk farther. Earlier studies indicated a decreasing degree of utilization with an increasing distance from water. In this study, where a variety of species was available, cattle readily grazed a distance from water to obtain certain species. It is suggested that an important tool in obtaining better livestock distribution would be to encourage the growth of palatable species at a distance from water.}, keywords = {grazing distribution, hereford, livestock distribution, Santa Gertrudis, southern New Mexico}, url = {/files/bibliography/104.pdf}, author = {C.H. Herbel and F.N. Ares and Nelson, A.B.} } @proceedings {52447, title = {Grazing management on semidesert range in southern New Mexico}, year = {1967}, month = {1967}, pages = {12}, address = {Las Cruces, NM}, keywords = {grazing management, semidesert range, southern New Mexico}, author = {C.H. Herbel} } @mastersthesis {52453, title = {Growth and propagation potential of selected New Mexico native plants for commercial use}, year = {1967}, note = {//LOCAL//NONE//}, month = {1967}, pages = {28}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {Twenty-one selected native plant species from New Mexico and vicinity were studied to evaluate their potential for cultivation. Growth response of transplants, cuttings, and seeds were used to make this evaluation.... Those plant species studied which indicate high potential for propagation are: Dyscodia pentechacta (DC.) Robins, Haplopappae laricifolius Gray, Fendlera rupicola Gray, Philadophus micorphyllus Gray, Robinia neonaxicana Gray, Ungnadin speciosa, Endl., Zinnia mumila Gray.}, keywords = {dissertation, dissertations, plant, germination, plant, survival, plant, transplants, theses, thesis}, author = {Redding, P. D.} } @article {52471, title = {Germination and growth of some semidesert grassland species treated with aqueous extract from creosotebush}, journal = {Ecology}, volume = {47}, year = {1966}, month = {1966}, pages = {775-781}, abstract = {The effects of aqueous extracts from creosotebush (Larrea tridentafa) material on germination and initial growth of black grama (Bouteloua eriopoda), bush muhly (Muhlenbergia porteri) and creosotebush were studied. There was no apparent difference among extracts obtained from the various creosotebush plant parts. An aqueous extract from leaves and twigs significantly reduced germination of black grama caryopses, but the germination of bush muhly caryopses and creosotebush seeds (removed from the carpels) was not affected. Less concentrated extracts did not significantly reduce germination of the test species. However, radicle and plumule growth of black grama and bush muhly were significantly reduced by all extracts. Apparently, the relatively low osmotic concentrations or the moderate pH{\textquoteright}s were not responsible for these reductions in growth. Comparisons among creosotebush seeds (removed from the carpel) watered with a carpel extract and a water-mannitol solution of the same osmotic concentration and carpels treated with water indicated a structural characteristic or a nonwater-soluble chemical compound in the carpel which inhibits germination of creosotebush. Germination of creosote bush seeds treated with water-mannitol solutions of 1.50, 3.50, 5.00 and 7.00 atm osmotic concentration was significantly reduced as compared to those treated with low concentrations simulating field capacity. Nutrient solution recycled for 37 days around the roots of creosotebush plants growing in a gravel-sand substratum was not inhibitory to germination or initial growth. In a pot test, creosotebush extracts created a crust on the soil surface which reduced the infiltration rate of water. Some of the preceding factors may possibly contribute to the degeneration of grassland areas where creosotebush is present.}, keywords = {aqueous extract, creosotebush, germination, semidesert grassland species}, url = {/files/bibliography/100.pdf}, author = {Knipe, D. and C.H. Herbel} } @proceedings {52480, title = {Geomorphic surfaces along the Rio Grande Valley from El Paso, Texas to Caballo Reservoir, New Mexico}, volume = {Sixteenth Field Conference}, year = {1965}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1965}, pages = {188-198}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, abstract = {The flood plain of the Rio Grande in southern New Mexico and Texas near El Paso is flanked by an ascending sequence of geomorphic surfaces graded to successively higher and older flood-plain positions of the ancestral river. These valley-border surfaces represent major cycles of erosion, accompanied by lesser amounts of backfilling, and they are in turn inset below remnants of an early (?) to mid-Pleistocene complex of basin-filled surfaces.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, Desert Project, geology,Cenozoic, geomorphology, Cenozoic, proceeding, proceedings, soil, geomorphology relationships}, author = {J. Hawley} } @article {52505, title = {Genetic effect of cardiac ventricular septal defect in Hereford cattle}, journal = {Veterinary Medicine}, volume = {57}, year = {1962}, note = {//??//NONE//(New Mexico Agr. Experiment Station Journal Article 189)}, month = {1962}, pages = {965-968}, keywords = {article, articles, cattle,genetics, genetics,cattle, journal, journals}, author = {Belling, T. H.} } @article {52506, title = {Genetic analysis of economic characteristics of young Hereford cattle}, journal = {Journal of Animal Science}, volume = {21}, year = {1962}, note = {//??//NONE//(New Mexico Agr. Exp. Station Journal Article 166)//}, month = {1962}, pages = {101-107}, keywords = {article, articles, cattle,genetics, genetics, also SEE , genetics,cattle, journal, journals}, author = {Blackwell, R. L. and Knox, J. H. and Shelby, C. E. and Clark, R. T.} } @article {52508, title = {Grazing values and management of black grama and tobosa grasslands and associated shrub ranges of the Southwest}, year = {1962}, month = {1962}, pages = {56 }, abstract = {Optimum production of livestock on black grama and tobosa grasslands and associated shrub ranges of the Southwest depends on proper management of the forage resource. In this region, periods of low precipitation are frequent and fluctuations in seasonal and annual amounts are extreme. Under these circumstances, range livestock operators are faced with perplexing problems of how to maintain stability and continuity of their enterprises. Too often ranchers and land managers are handicapped by not having long-term records of forage production to give them a better idea of range potential. Studies of management practices and effects of weather on black grama and tobosa grasslands and associated shrub ranges have been underway in southern New Mexico since 1912. The Jornada Experimental Range was established that year as a 193,394-acre tract 23 miles northeast of Las Cruces. Because its vegetation, soils, and climate are sufficiently comparable to that of more than 26 million acres of black grama, tobosa and associated shrub ranges in the Southwest, research results can be applied directly to much of this area. Many of the principles of management also are adaptable to other semidesert grass-shrub ranges in Arizona and Texas. The experimental work on the Jornada has been a combination of empirical studies on large range pastures and detailed studies of climate, soils and important forage plants and range types (Campbell, 1940). These studies have two main objectives: (1) to gain an understanding of the forage resource, and (2) to determine the methods of management best suited to the region.}, keywords = {black grama, forage production, government publication, grasslands, livestock production, shrub ranges, tobosa}, url = {/files/bibliography/087.pdf}, author = {Paulsen, H.A., Jr. and F.N. Ares} } @article {52618, title = {Growth and reproduction of Yucca elata}, journal = {Ecology}, volume = {13}, number = {4}, year = {1932}, month = {October 1932}, pages = {364-374}, abstract = {

Yucca elata, Engelm., locally called soapweed, is a long-lived perennial of the Liliaceae. Wooton and Standley (1915) describe the plant as follows: "Stems conspicuous in old plants, reaching a height of 3 to 4 meters, naked below, clothed with a tuft of leaves above; inflorescence a much branched panicle, leaves 10 mm wide or less." Average plants in southern New Mexico vary from 3 to 6 feet in height, but specimens as tall as 30 feet have been observed.

}, keywords = {description, growth, reproduction, Yucca elata}, url = {/files/bibliography/021.pdf}, author = {R.S. Campbell and Keller, J.G.} } @article {52635, title = {Geologic structure of parts of New Mexico}, year = {1922}, note = {//??//NONE//}, month = {1922}, keywords = {book, books, chapter, chapters, geology, geomorphology, report, reports}, isbn = {Bulletin 726-E}, author = {Darton, N. H.} } @article {52649, title = {The grasses and grass-like plants of New Mexico}, year = {1911}, note = {//??//NONE//updated 8/21/2006}, month = {1911}, keywords = {book, books, chapter, chapters, grass,list, list,grass-like plants, list,grasses, report, reports}, isbn = {Bulletin 81}, author = {Wooton, E.O. and Standley, P. C.} } @article {52652, title = {Geology and underground water conditions of the Jornada del Muerto, New Mexico}, year = {1905}, note = {//??//NONE//}, month = {1905}, keywords = {book, books, chapter, chapters, geology,underground water, report, reports, water,underground}, isbn = {Paper 123}, author = {Keyes, C. R.} }