@proceedings {JRN55367, title = {Understanding Collaboration in a Research Network: The Role of Trust}, year = {2022}, month = {3/30/2022}, abstract = {The agricultural research community has pushed to increase the impact of research via the development of scientific networks. These networks strive for multi-site, coordinated research, which is frequently administered within an organizational structure. In any research process, there are uncertainties regarding its outcomes, which can be compounded in a network setting because research must fit within a researcher social network and organizational structure. Researchers must be willing to accept a level of vulnerability in relation to their research outcomes. Given such a dynamic, it is likely that trust will play an important role in researchers{\textquoteright} involvement with the network organization. To understand the role of trust in collaboration, we evaluated researcher trust, collaboration behavior, and behavioral intentions within a science network using an online questionnaire. We asked researchers about their research activities and intentions, trust, and their perspectives regarding the research network. We found support for four types of trust among researchers: affective, procedural, dispositional and rational. Using a regression analysis, we found that trust does play a role in researchers{\textquoteright} behavioral intentions, however, not all forms of trust were related to behavioral intentions nor were they positively associated with collaboration. Based upon our findings, we provide theoretical insights about collaboration, as well as, recommendations to help foster collaboration within research networks and among researchers more generally.}, keywords = {behavioral intentions, networks, organizational structure, scientific networks}, author = {Zachary Hurst and Meredith Gwendwr and Claire Friedrichsen and J. D. Wulfhorst} } @proceedings {JRN55397, title = {The use of heritage cattle breeds as a mitigation strategy for solving new challenges imposed by climate change in Chihuahuan Desert rangelands of the southwestern United States}, year = {2022}, month = {8/10/2022}, abstract = {The study{\textquoteright}s objective involves a compilation of four publications comparing conventional (Angus X Hereford; AH) vs. heritage (Raramuri Criollo; RC) breeds foraging habits, heat tolerance, and cow-calf interactions using telemetry devices under the context of a future mitigation strategy of climate change. AH and RC cows grazed separately in two adjacent pastures in a crossover design during summer and winter for three consecutive years. Rectal fecal samples were collected twice in each cow{\textquoteright}s deployment to analyze diet composition. A subgroup of individuals in each herd was fitted with sensors to track their location (GPS collars), body temperature (iButton loggers), and cow-calf contact events (Proximity loggers). RC cows traveled farther, spent less time resting, more time grazing, and explored larger areas than their AH counterparts. RC cows showed a higher preference for patches with high shrub density and avoided areas with a high density of black grama during winter, consistent with the fDNA analysis on diet composition. During summer, RC cows maintained a lower body temperature than their AH counterparts, providing additional evidence for the differences observed in foraging patterns. RC calves appeared to impose fewer constraints on their dams{\textquoteright} movement and activity patterns. Nursing RC dams covered a daily grazing area almost three times larger than their AH counterparts. Differences in foraging strategies documented in this study provide support for the hypothesis that Raramuri Criollo (heritage breed) cattle are better equipped to cope with hotter and drier climates and better able to use forage resources that are becoming increasingly variable in space and time.}, author = {S. Nyamuryekung{\textquoteright}e and Andr{\'e}s F. Cibils and Richard E. Estell and S. A. Utsumi and Matthew M. McIntosh and S. Spiegal} } @article {JRN55312, title = {Use of PhenoCam Measurements and Image Analysis to Inform the ALMANAC Process-based Simulation Model}, journal = {Journal of Experimental Agriculture International}, volume = {43}, year = {2021}, month = {07/05/2021}, pages = {120-144}, abstract = {Near-surface remote sensing has been used to document seasonal growth patterns (i.e., phenology) for plant communities in diverse habitats. This study quantified greenness from PhenoCam image time series, and applied Beer{\textquoteright}s law with established extinction coefficients to compare leaf area index (LAI) development with the ALMANAC model. We examined patterns and modeled LAI at eight agroecosystem sites as part of the Long-Term Agroecosystem Research (LTAR) network selected for their diversity and amount of and quality of available data. Regions of interest (ROIs) in PhenoCam images were used to derived Green Chromatic Coordinate (GCC) at each site. Next, photos were analyzed in the L*A*B* color space in ImageJ to determine greenness and then the site was simulated in ALMANAC. Finally, the GCC and greenness data were converted to LAI and compared with modeled LAI. Results indicate that PhenoCam time series imagery can be used to improve parameters for leaf area development in ALMANAC by adjusting parameter values to better match LAI derived values in diverse environments. Soybeans, mesquite, and maize produced the most successful match between the model simulations and PhenoCam data out of the eight species simulated. This study represents, to our knowledge, the first independent evaluation of the ALMANAC process-based plant growth model with imagery in agroecosystems available from the PhenoCam network. The results show how PhenoCam data can make a valuable contribution to parameter determination in process-based models, making these models much more realistic. The impact of these conclusions can be increased as the methods are further refined.}, keywords = {PhenoCam Network; ALMANAC model; ImageJ; phenology; green chromatic coordinate; Leaf Area Index (LAI)}, url = {files/bibliography/21-029.pdf}, author = {Jacqueline Jacot and J.R. Kiniry and Amber S. Williams and Addison Coronel and Jianzhong Su and Gretchen R. Miller and Binayak Mohanty and Amartya Saha and Nuria Gomez-Casanovas and Jane M. F. Johnson and Dawn M. Browning} } @conference {JRN55238, title = {Understanding ecological condition and change on rangelands managed by the Bureau of Land Management: An initial report}, booktitle = {Ecological Society of America}, year = {2020}, month = {08/2020}, address = {Virtual Conference}, abstract = {Background: Rangelands in the United States encompass a diversity of ecosystems, including the prairies of the Midwest and Great Plains, sagebrush shrublands, deserts, mountain meadows, and tundra in Alaska. The Bureau of Land Management (the BLM) manages nearly 244.4 million acres of federal lands in the lower 48 states and Alaska, of which 194 million are rangelands. The BLM{\textquoteright}s standardized rangeland monitoring program, the Assessment, Inventory, and Monitoring (AIM) program, is designed to determine the status, condition, and trend of BLM{\textquoteright}s rangeland ecosystems. These monitoring data provide a unique opportunity to understand the ecological condition of western United States rangelands at both local and ecoregional scales. Here we present preliminary results from the first 8 years of the national AIM monitoring program. We explore how dynamics of biotic integrity - including non-native invasive species, hydrologic function, and soil/site stability at the ecoregional scale are influenced by both wildfire and BLM vegetation treatment and restoration activities. ~ Results: We analyzed AIM monitoring data on BLM land in 11 Level II and Level III ecoregions in the western United States between 2011 and 2018. During that same period, over 21 million acres (12 \%) of BLM lands burned in wildfire, which correlated to an increase in invasive species. Non-native invasive plants were found in all ecoregions and were present on 57\% of BLM acres in 2011 compared to 62\% of BLM acres in 2018. Non-native invasive plants also increased on BLM rangelands, with percent of rangelands where invasive plants were common (>25\% of vegetation cover) increasing from about 17\% in 2011 to over 25\% in 2018. In response to wildfire and invasive species threats and wildlife habitat loss, BLM completed over 500 vegetation treatments on 8.4 million acres, including post-fire seedings, weed removal, fuels reduction, and encroaching shrub and tree species removal. Despite the wildfire and invasive species increase, ecological condition appears to be static or improving on all ecoregions except the Madrean Archipelago.~In 2011, an estimated 114 million BLM acres were within the historical range of variability for biotic integrity, hydrologic function, and soil and site stability compared to 118 million acres in 2018. These results indicate a nuanced story of ecological condition of BLM lands and highlight the importance of continued monitoring as these trends may be further understood over longer time periods. While current conditions are stable, non-native invasive species spread, accelerated by wildfire, could have broad impact on these rangeland ecosystems. Poster $\#$ 88711.}, author = {Rachel Burke and Sarah McCord and Emily Kachergis and Jeffries, Michelle and Melissa Dickard and Greene, Adam and Jeffrey E. Herrick and Nika Lepak and David Pilliod and Karen Prentice} } @conference {JRN55301, title = {Using manureshed management to connect distant links of the beef supply chain}, booktitle = {ASA-CSSA-SSSA Annual Meeting Abstracts}, year = {2020}, month = {11/09/2020}, abstract = {Manure management in US beef is complex, complicated by the diffuse and diverse nature of the industry, but also offering numerous points of opportunity as beef cattle progress from calf to background to finishing stages. In support of the manureshed vision, we review the networks that must be engaged to systematically coordinate manure management. Through case studies and original analysis, we point to the realities of today{\textquoteright}s industry and the opportunities to implement strategic manure management that ensures the sustainable management of manure resources.}, author = {S. Spiegal and Meredith Gwendwr and Maria Silveira and Colton K Flynn and Jo{\~a}o M.B. Vendramini and Peter J. A. Kleinman} } @article {JRN55243, title = {Using geospatial methods to measure the risk of environmental persistence of avian influenza virus in South Carolina}, journal = {Spatial and Spatio-temporal Epidemiology}, volume = {34}, year = {2020}, month = {05/2020}, chapter = {100342}, abstract = {Avian influenza (AIV) is a highly contagious virus that can infect both wild birds and domestic poultry. This study aimed to define areas within the state of South Carolina (SC) at heightened risk for environmental persistence of AIV using geospatial methods. Environmental factors known to influence AIV survival were identified through the published literature and using a multi-criteria decision analysis with GIS was performed. Risk was defined using five categories following the World Organization for Animal Health Risk Assessment Guidelines. Less than 1\% of 1km grid cells in SC showed a high risk of AIV per- sistence. Approximately 2\% - 17\% of counties with high or very high environmental risk also had medium to very high numbers of commercial poultry operations. Results can be used to improve surveillance activities and to inform biosecurity practices and emergency preparedness efforts.}, keywords = {Avian influenza, Geospatial, modeling, poultry, Risk map, Waterfowl}, doi = {https://doi.org/10.1016/j.sste.2020.100342}, url = {files/bibliography/20-032.pdf}, author = {Stenkamp-Strahm, Chloe and Patyk, Kelly and McCool-Eye, Mary Jane and Fox, Andrew and John Humphreys and Angela James and South, David and Magzamen, Sheryl} } @conference {JRN55240, title = {Using benchmarks to assess management objectives across ecological domains}, booktitle = {Ecological Society of America}, year = {2020}, month = {02/2020}, address = {Salt Lake City, Utah}, abstract = {Background: Adaptive management of natural resources is an iterative process of planning and documenting objectives, implementing management actions, monitoring, and adjusting future actions. Ecological monitoring has been a weak link of the adaptive management process in the past but that is changing. In an increasingly data-rich environment, setting quantifiable, specific, and informative management objectives is essential for successfully applying data to decision-making. Communicating these objectives to a broad audience including public land managers and practitioners, the scientific community, and the general public is increasingly becoming a greater challenge than data availability. The Bureau of Land Management (BLM) has established the Assessment, Inventory and Monitoring (AIM) program, a standardized monitoring program designed to determine the status, condition, and trend of terrestrial and lotic resources on public land. We demonstrate a framework for creating, organizing, and utilizing quantitative benchmarks for indicators specific to wildlife habitat, invasive species, soil and site stability, and water quality using the AIM strategy. Our objectives are to provide a flexible and accessible framework for documenting management goals, defining monitoring objectives, selecting appropriate ecological indicators and documenting specific quantitative benchmarks within an area of interest. Using this approach, monitoring data collected using probabilistic sample designs can be used to assess the proportion of management areas meeting benchmarks for management objectives and thus provide clear and objective support as to whether management actions should be reviewed or amended. Results: This benchmarking process is exemplified through a grazing permit renewal analysis based on watershed land health evaluations in central Wyoming. We used a design-based weighted analysis approach using a range of indicators for terrestrial and lotic ecosystem structure and function. The indicators chosen were guided by BLM Rangeland Health Standards and included: lotic fine sediment content, specific conductance, nitrogen and phosphorous content, abundance of macroinvertebrates, amount of bare soil, and upland vegetative cover including cover of perennial grass species, non-native invasive species, and big sagebrush (Artemisia tridentata). Benchmarks were set using predicted natural condition models, state water quality standards, and desired condition based on management goals and professional judgement. Results concluded the allotment had major departure from expected natural conditions for non-native invasive species, macroinvertebrate abundance, specific conductance, and total phosphorus while meeting objectives for stream nitrogen content, perennial grass cover, and sagebrush cover. This approach enables potential management trade-offs and synergies to be identified and addressed across objectives from multiple disciplines while improving the clarity of the decision-making process. Paper $\#$88722.}, author = {Alex Traynor and Scott W. Miller and Sarah McCord and Nicholas Webb and Nelson Stauffer and Emily Kachergis and Newbury, Cheryl and Jennifer Courtright and Nicole Cappuccio} } @conference {JRN55164, title = {Using ecological site information to develop drought response strategies}, booktitle = {Universities Council on Water Resources}, year = {2019}, month = {06/11/2019}, abstract = {

Ecological Sites (ES) are interpretive groupings of static soil properties with unique climate, geomorphic and edaphic properties.\  They can be mapped using National Cooperative Soil Survey tools and are supported by standardized, databased descriptions that include spatial biophysical attributes (eg soil depth, texture) and temporal behaviors (eg vegetation dynamics, disturbance responses).\  In this project, we used ecological site information to evaluate the potential impact of drought conditions and to develop potential response strategies in two Major Land Resource Areas (MLRAs).\  MLRA 69 in SE Colorado is characterized by mollisols, short grass prairie vegetation and extensive livestock grazing/dryland small grains.\  MLRA in SE Arizona is characterized by aridisols, desert shrub/oak woodland/desert grassland vegetation and is used for livestock grazing.\  We developed drought vulnerability assessment criteria to rank impacts on specific management units and to serve as a basis for developing strategic responses.\  The primary threat of drought in MLRA 69 is reduced livestock forage and mid-term suppression of forage production post-drought, including ranch-level economic impacts.\ \  Soils and vegetation are relatively well-adapted to drought and have substantial capacity for recovery, but economic stability is more fragile.\  MLRA 41 has experienced, and continues to, experience short, medium and long-term drought impacts.\  Short term impacts include reduced forage production; medium term impacts are primarily suppressed forage production post-drought; and long-term impacts include grass to shrub transitions and soil degradation.\  Within each MLRA, there were substantial differences among ES, both in terms of reduction of forage production and in long-term recovery post drought.\  These differences offer opportunities for managers to develop drought responses by selectively destocking management units as drought progresses and restocking post drought.

}, author = {Joel R. Brown and J.T. Reyes and Emile H. Elias and Caitriana Steele and Wyndham, A.} } @conference {JRN55139, title = {Using machine learning to model complex landscapes: predicting the geographic range of Vesicular Stomatitis across the western United States}, booktitle = {Ecological Society of America Abstracts}, year = {2019}, abstract = {

Complex relationships among a virus, host, vector, and environment challenge prediction of disease spread through time and space. In addition, changing climate and land use regimes result in novel risk to biota and emphasize the need to improve understanding of mechanisms governing disease. Vesicular Stomatitis (VS) is the most common vesicular livestock disease in North America. Recent investigations have characterized how VS generally spreads from its endemic range in Central America northward through the western United States (US). Despite regional insights into VS, there is still a need to explore the broader environmental relationships limiting the spatial extent of VS to improve our understanding of the potential geographic range. The objective of this study was to model the potential range of VS in the US under current and alternative climate scenarios. The current model of VS occurrence was constructed using a transdisciplinary big data-model integration approach coupled with machine learning to predict the potential maxima of VS occurrence using disparate data sources representing soil, climate, land use, host, and vector properties. An information-theoretic approach was used to construct and select a model which was projected into potential future climate scenarios. The current extent of VS is largely confined to the western portion of the United States. The probability of occurrence was most associated with low summer surface runoff, low winter and summer precipitation, moderate summer and fall vegetation greenness, and increased maximum winter temperatures. Predictions using alternative climate data suggest that reductions in NDVI and increases in temperature can result in predicted occurrences that are spatially explicit and non-uniform in their direction of change. Our results suggest that the result of modifications to the environment can be complex and may either mitigate or increase occurrence risks. We suggest that these results can help define priority areas for research, monitoring, and mitigation efforts. Moreover, this analysis provides an illustration of the robustness of the big data-model integration approach in exploring complex problems at multiple scales.

}, author = {N. Dylan Burruss and Debra C. Peters and Luis L Rodriguez and David McVey and Emile H. Elias and Angela Pelzel-McCluskey and Heather Savoy and J. D. Derner and Steven H. Pauszek} } @article {JRN55150, title = {Understanding future threats to western rangelands: Modeling the performance of grazing strategies in the face of environmental change}, journal = {Western Agriculture Economics Association}, volume = {17}, year = {2019}, month = {04/2019}, pages = {40-45}, chapter = {40}, abstract = {

Rangeland ecosystems comprise 30\% of the land area in the United States (Havstad et al. 2009), the health and resilience of which produce a variety of economic and social benefits. Rangelands are a dynamic resource; decisions made today affect range conditions over subsequent seasons, and conditions realized today are the product of past management decisions. Therefore, rangelands really must be managed over time. Historically, the economics literature on rangelands has focused predominantly on selecting livestock grazing strategies (namely stocking rates) to maximize economic net benefits. More recently, economic studies have incorporated insights from ecological research into models, adding ecological feedbacks to models as well as the effects of, for example, stochastic weather and invasive species. As changing climates alter the risks to rangeland ecology, through establishment and spread of invasive species and transition of rangelands away from native perennial grasses, the economic performance of existing livestock grazing strategies may need to be re-evaluated. While economists seek out grazing strategies that maximize profit, livestock producers and land management agencies often rely on rules of thumb, such as {\textquotedblleft}take half, leave half{\textquotedblright} or {\textquotedblleft}50\% utilization{\textquotedblright} rule. The dynamic, economic, and ecological impacts that arise from rangeland managers using this rule of thumb are still poorly understood, especially under changing environmental conditions. So, the question arises: will continued use of the traditional 50\% utilization rule of thumb benefit or harm the health of rangeland ecosystems and producers in the face of a changing climate and invasive plant species?

}, doi = {10.22004/ag.econ.287313}, url = {files/bibliography/19-020.pdf}, author = {Torell, Gregory L and Lee, Katherine D. and Caitriana Steele} } @conference {JRN54998, title = {Using Ecological Site Descriptions and State and Transition Models to inform native plant restoration strategies}, booktitle = {72nd Society for Range Management International Meeting}, year = {2019}, month = {02/2019}, publisher = {Society for Range Management Meeting Abstracts}, organization = {Society for Range Management Meeting Abstracts}, address = {Minneapolis, Minnesota}, abstract = {

The 2008 Tejon Ranch Conservation and Land Use Agreement required an adaptive management plan for over 200,000 acres of conserved lands, including vast expanses of rangelands on which the landowner retained the right to graze cattle. Ecological Site Descriptions (ESDs) and State and Transition Models (STMs) were developed for over 100,000 acres of grasslands using a field-based, data-driven approach. In the southern San Joaquin Valley side of the ranch, we identified ecological sites that support states dominated by native plant communities with high native forb species diversity and abundance. These forb-dominated communities have naturally lower fall biomass, as measured by Residual Dry Matter (RDM), than nonnative annual grass-dominated communities, and support several vertebrate species of conservation concern (e.g., San Joaquin kit fox and blunt-nosed leopard lizard) that are hypothesized to prefer low plant biomass conditions. By linking STMs with field data about temporally dynamic environmental conditions, we identified the interactions between annual Mediterranean weather patterns and ecological sites as drivers of native and nonnative plant-dominated community phases and states, which in turn influence conditions for other conservation targets. Our adaptive management plan used ESDs paired with STMs to identify the spatial distribution of grassland types and focal species, understand drivers of the temporal transitions of specific grassland types and the feasibility of achieving desired conditions, and hypothesize grazing strategies to promote conservation values. For instance, a recommended practice to achieve conservation objectives in the Holocene Alluvial Flats Ecological Site is to maintain RDM \<500 lbs/acre, particularly in years with high levels of rain early in the growing season that encourages nonnative annual grass growth and high RDM conditions. To help facilitate this practice, the Conservancy and the ranchers cooperated to install new fences and waters in pastures supporting Holocene Alluvial Flats Ecological Sites.

}, author = {White, Michael and S. Spiegal and James Bartolome} } @proceedings {JRN54863, title = {Understanding spatial variability in perennial grass restoration following shrub removal in the Chihuahuan Desert: The restore New Mexico collaborative monitoring program}, volume = {January 28-February 2, 2018}, year = {2018}, month = {01/28/2018}, publisher = {Society for Range Management Meeting Proceedings}, address = {Reno, NV}, abstract = {

Grassland to shrubland transitions are well documented throughout the desert grassland region of the Chihuahuan Desert. These transitions were triggered in the early 20th century by overgrazing of perennial grasses during drought periods, loss of fire regimes, and seed dispersal by livestock. Shrublands dominated by C3 species are highly resilient to natural disturbances, so herbicides specific to the C3 photosynthetic pathway are used to reduce the competitive preemption of soil water resources by shrubs and trigger the recovery of C4 perennial grasses. Anecdotally, there is evidence that shrub management treatments have been effective in some cases, but not in others, creating controversy about their value. As part of the Restore New Mexico partnership, we initiated a region-scale, long-term monitoring experiment embedded within shrub management treatments beginning in 2007. Within shrub management areas, we created treatment and control plots that were matched according to soils/ecological sites and initial state prior to treatments, such that control plots were excluded from treatment. Line-point intercept was used to measure cover prior to and after treatments. In addition, we sampled older treatments (2004 and earlier) using space-for-time substitution assumptions. Our records to date indicate that 1) treatments are generally effective in increasing perennial grass cover, 2) the composition of grasses that increase usually differs from that of putative reference states, creating {\textquotedblleft}novel ecosystems{\textquotedblright} and 3) soil and climate properties are related to the magnitude of grass response to treatments; specifically, loamy soils and drier climates yield reduced grass response. Experimental monitoring data can be used to refine restoration approaches and resolve controversies about them.

}, author = {Brandon T Bestelmeyer and Laura M. Burkett and Leticia Lister} } @conference {JRN54945, title = {Using ecological sites and state and transition models to support objective based conservation planning}, booktitle = {73rd Soil and Water Conservation Society International Conference}, year = {2018}, month = {07/2018}, address = {Albuquerque}, abstract = {

Use of Ecological Site Information, Ecological Site Descriptions (ESDs), and State and Transition Models (STMs) in the 9 Step Conservation Planning Process on all land uses will be covered to support objective based conservation planning. ESDs provide land managers the information needed for evaluating land use suitability, response to different management activities or disturbance processes, and ability to sustain productivity over the long term. Integrating ESDs is the most spatially and temporally relevant model for a conservation planner to use for multiple land uses when discussing client objectives, defining resource concerns, conducting inventories, selecting applicable practices/management measures, monitoring effects, and supplying feedback. Site specific use of STMs assure that conservation planners collect, organize, manage, and apply ecologically based conservation planning information. STMs describe a range of resource conditions (e.g., states and phases) and processes (e.g., time, triggers, succession, disturbances, management activities/practices) related to transitions in each land use. Development of hierarchical nested STMs for major land uses and sub-land uses that describe a common range of resource conditions, along with the conservation practices/management systems that can drive a desired resource change, allow the planner to focus on applicable land use(s) that apply. STMs can also be utilized to avoid making common conservation planning mistakes, such as utilizing practices that are not well-suited or applying practices that have negative effect on resource conditions.\  Transitions between states include information about conservation practices and adaptive management concepts that can achieve desired resource conditions. States and phases are explicitly connected to soil health, soil health indicators, and soil health management systems; and can be utilized across the country on a wide range conditions to guide conservation planning.

}, author = {Brandon T Bestelmeyer and Joel R. Brown and Strait, Richard} } @conference {JRN54672, title = {Using state-and-transition models to evaluate impacts of land cover change on wind erosion}, booktitle = {Society for Range Management Meeting Abstracts}, volume = {Jan 29 - Feb 02, 2017}, year = {2017}, month = {01/2017}, abstract = {
Wind erosion of rangeland soils is a global problem exacerbated by land cover change. Despite efforts to quantify the impacts of land cover change on wind erosion, assessment uncertainty remains large. We address this uncertainty by evaluating the application of ecological sites and state-and-transition models for detecting and describing the impacts of land cover change on wind erosion. We couple a geodatabase of ecological site information with atmospheric data from the Weather Research and Forecasting (WRF) model to run a dust emission model at 1 km spatial resolution over a study area in the northern Chihuahuan Desert, New Mexico, USA. We evaluate spatiotemporal patterns of modelled horizontal sediment mass flux and dust emission in the context of ecological sites and their states; representing a diversity of land cover types. Our results demonstrate how the impacts of land cover change on wind erosion can be quantified, compared across land cover classes, and interpreted in the context of an ecological model that encapsulates land management intensity and change. Results also reveal weaknesses in the dust emission model{\textquoteright}s soil characterisation and drag partition scheme, which were largely insensitive to the impacts of land cover change. New models that address these weaknesses, coupled with the ecological site framework and field measurements across land cover types, could significantly reduce assessment uncertainties and provide opportunities for identifying land management options.
}, author = {Nicholas Webb and Magda Galloza and M. Bleiweiss and Craig Winters and E.L. Ayers and Jeffrey E. Herrick} } @article {JRN54685, title = {Using ecological site information to improve landscape management for ecosystem services}, journal = {Rangelands}, volume = {38:318-321}, year = {2016}, month = {12/2016}, abstract = {

People and their societies, have a complicated relationship with land. The unofficial patron saint of ecologists, Aldo Leopold, in {\textquotedblleft}The Sand County Almanac,{\textquotedblright} traced the modern human relationship with land from a purely economic to an ecologically based approach, culminating in his {\textquotedblleft} Land Ethic.{\textquotedblright} \ In this ground-breaking and influential essay, Leopold proposed that {\textquotedblleft}a land ethic changes the role of Homo sapiens from conqueror of the land-community to plain member and citizen of it.{\textquotedblright} \ The main idea embodied in this essay was that good land management was an individual and community responsibility that transcended pure economics. \ While Leopold focused primarily on the cooperative nature of the human relationship to land, a secondary, but just as important, part of the essay was that {\textquotedblleft}The land ethic simply enlarges the boundaries of the community to include soils, waters, plants and animals, or collectively, the land."

}, doi = {10.1016/j.rala.2016.10.011}, url = {files/bibliography/16-035.pdf}, author = {Joel R. Brown and Kris Havstad} } @conference {JRN54636, title = {Using shadow to reformulate wind erosion modelling, mapping and monitoring}, booktitle = {International Conference on Aeolian Research}, year = {2016}, month = {07/2016}, publisher = {International Conference on Aeolian Research}, organization = {International Conference on Aeolian Research}, address = {Mildura, Australia}, abstract = {
Wind erosion and dust emission models are required to assess the impacts of dust in the Earth system. We describe a need in aeolian research to adequately represent the spatial variability and particularly the area average of the key aerodynamic properties which influence these models and our understanding of the processes. The models are underpinned by a geometric property (lateral cover; L) used to characterise the aerodynamic roughness (sheltered area or wakes) of the Earth{\textquoteright}s surface and calibrate the momentum it extracts from the wind. We reveal an error in the calculation of L and demonstrate that significant aerodynamic interactions between roughness elements and their sheltered areas have been omitted particularly under sparse surface roughness. We describe a solution which develops earlier work to establish a relation between sheltered area and the proportion of shadow over a given area; the inverse of direct beam directional hemispherical reflectance (black sky albedo; BSA). We show direct relations between BSA and wind tunnel measurements and thereby provide direct calibrations of key aerodynamic properties. We demonstrate how those properties can be retrieved from BSA from any platform (mast, aircraft, satellite). MODIS BSA across Australia is used to illustrate how areal estimates of aerodynamic properties improve wind erosion modelling, mapping and monitoring frequently in time (8 days) and space (500 m) across scales of variation (grain to landscape). We show that this approach provides new opportunities to investigate the dynamics of wind erosion in space and time and elucidate aeolian processes across scales.
}, author = {A. Chappell and Nicholas Webb} } @book {JRN54578, title = {Unlocking the sustainable potential of land resources evaluation systems, strategies and tools}, year = {2016}, pages = {89 pp.}, publisher = {United Nations Environment Program (UNEP)}, organization = {United Nations Environment Program (UNEP)}, abstract = {

Better matching of land use with its sustainable potential is a {\textquotedblleft}no-regrets{\textquotedblright} strategy for sustainably increasing agricultural production on existing land, targeting restoration efforts to where they are likely to be most successful, and guiding biodiversity conservation initiatives. Land potential is defined as the inherent, long-term potential of the land to sustainably generate ecosystem services. This report provides an introduction to land potential evaluation systems, strategies and tools necessary to implement this strategy. It provides information that both private landowners and policymakers can use to increase long-term productivity and profitability, while at the same time addressing global objectives defined through land-related Sustainable Development Goals, and particularly 15.3 (land degradation neutrality). The focus of the report is on the inherent long-term (decades) potential of the land to sustainably generate ecosystem services, based on soils, topography and climate. In general, land that can sustainably support higher levels of vegetation production, including crop, forage and tree, has higher potential. Short-term land potential (1-5 years) depends on a combination of long-term potential, weather, and the current condition of the land (e.g. fertility, compaction, current vegetation cover). Matching land use with its potential determines whether the inherent long-term potential is sustainably realized. Sustainability depends on (1) potential degradation resistance, and (2) potential resilience, which is the capacity to recover from degradation. Land with similar potential should therefore respond similarly to management. Policymakers have a tremendous number of opportunities to leverage land evaluations to both increase returns on investments, while minimizing risks of catastrophic failures, such as Britain{\textquoteright}s post-world war II peanut scheme in Tanzania, and the United States Dust Bowl, which resulted from an ill-informed agricultural expansion in the early part of the 20th century. Policy options for applying land evaluation include, but are not limited to (1). setting realistic, practical targets for land degradation neutrality, (2). general land use planning to decide which lands should be reserved for agricultural production and biodiversity conservation, (3). agricultural land use planning to sustainably increase food security and the profitability of the farming sector, (4). land reform and redistribution to ensure that (a) objectives for equitability are met and (b) tract sizes meet requirements for minimum economic production units, and (c) providing new landowners with appropriate information on the best available management practices specific to their land, (5). designing incentive and other programs to minimize degradation risk, and (6). optimizing climate change adaptation and mitigation initiatives by effectively targeting resources to where the greatest returns on investments are likely to occur. The report provides an overview of existing land evaluation systems, options for making them more useful by integrating resilience, and for applying land evaluation to policy.

}, url = {/files/bibliography/16-012.pdf}, author = {Jeffrey E. Herrick and Arnalds, O. and Brandon T Bestelmeyer and Brignezu, S. and G. Han and Mari-Vaughn V. Johnson and Montanarella, L. and Pengue, W. and Toth, G.} } @conference {JRN54616, title = {Utilizing soil polypedons to improve model performance for digital soil mapping}, booktitle = {Soil Science Society of America Meeting}, year = {2016}, month = {11/2016}, publisher = {Soil Science Society of America}, organization = {Soil Science Society of America}, address = {Phoenix, AZ}, abstract = {
Most digital soil mapping approaches that use point data to develop relationships with covariate data intersect sample locations with one raster pixel regardless of pixel size. Resulting models are subject to spurious values in covariate data which may limit model performance. An alternative approach is to aggregate covariate data for discernable soil bodies of similar soils, called polypedons, as training data for sample locations. Our objective was to explore the utility of different aggregation schemes of covariate data for soil mapping efforts and disaggregation of existing soil map units. Two study areas in semiarid rangelands of southeastern Arizona and southwestern New Mexico were the focus of this work. We present three examples that represent recent developments in the use of polypedon concepts for spatial predictions of soil components: 1) the effect of aggregating covariate data with a circular buffer around training data, 2) hand digitizing of polypedons to bolster sample size and overcome limitations of class imbalance for model development within a soil survey update, and 3) object-based image analysis for a data-driven approach of model development with polypedon units. A comparison of eight machine learning algorithms showed that a circular buffer size of 150 meters around training data had the best model performance (Kappa = 0.43) in the Arizona watershed. Radial support vector machine and random forest models performed best. In the New Mexico example, random forest models had with a Kappa of 0.16 for sampled points that improved to 0.95 with an additional 50 polypedon points for each class. Image segmentation of covariate data in the Arizona watershed using eCognition generated polypedons for model development without hand digitizing. Using polypedons as training data will improve spatial predictions of soil properties by maximizing information provided by covariate data and linking concepts of traditional soil survey and digital soil mapping.\ 
}, author = {Matthew Levi and Brandon T Bestelmeyer and David A. White II} } @conference {JRN54795, title = {Using Mid Infrared Spectroscopy to Predict the Decomposability of Soil Organic Matter Stored in Arctic Tundra Soils}, booktitle = {2016 American Geophysical Union Annual Meeting}, year = {2016}, month = {12/2017}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

The large amounts of organic matter stored in permafrost-region soils are preserved in a relatively undecomposed state by the cold and wet environmental conditions limiting decomposer activity. With pending climate changes and the potential for warming of Arctic soils, there is a need to better understand the amount and potential susceptibility to mineralization of the carbon stored in the soils of this region. Studies have suggested that soil C:N ratio or other indicators based on the molecular composition of soil organic matter could be good predictors of potential decomposability. In this study, we investigated the capability of Fourier-transform mid infrared spectroscopy (MidIR) spectroscopy to predict the evolution of carbon dioxide (CO2) produced by Arctic tundra soils during a 60-day laboratory incubation. Soils collected from four tundra sites on the Coastal Plain, and Arctic Foothills of the North Slope of Alaska were separated into active-layer organic, active-layer mineral, and upper permafrost and incubated at 1, 4, 8 and 16 {\textdegree}C. Carbon dioxide production was measured throughout the incubations. Total soil organic carbon (SOC) and total nitrogen (TN) concentrations, salt (0.5 M K2SO4) extractable organic matter (SEOM), and MidIR spectra of the soils were measured before and after incubation. Multivariate partial least squares (PLS) modeling was used to predict cumulative CO2 production, decay rates, and the other measurements. MidIR reliably estimated SOC and TN and SEOM concentrations. The MidIR prediction models of CO2 production were very good for active-layer mineral and upper permafrost soils and good for the active-layer organic soils. SEOM was also a very good predictor of CO2 produced during the incubations. Analysis of the standardized beta coefficients from the PLS models of CO2 production for the three soil layers indicated a small number (9) of influential spectral bands. Of these, bands associated with O-H and N-H stretch, carbonates, and ester C-O appeared to be most important for predicting CO2 production for both active-layer mineral and upper permafrost soils. Further analysis of these influential bands and their relationships to SEOM in soil will be explored. Our results show that the MidIR spectra contains valuable information that can be related to decomposability of soils.

}, author = {Matamala, R. and Zhoasheng Fan and Jastrow, J. and Liang, C. and Calderon, Francisco and Michaelson, G. and Ping, C. and Mishra, U. and Hofmann, S.} } @proceedings {JRN54633, title = {Use of a UAV-mounted video camera to assess feeding behavior of Raramuri Criollo cows}, year = {2016}, month = {07/2016}, pages = {1070-1072}, publisher = {International Rangeland Congress}, address = {Saskatchewan, Canada}, abstract = {

Interest in use of unmanned aerial vehicles in science has increased in recent years. It is predicted that they will be a preferred remote sensing platform for applications that inform sustainable rangeland management in the future. The objective of this study was to determine whether UAV video monitoring could be used to predict intake of food by beef cows. A series of tests were conducted in an arena with three food types and video footage was obtained with a quadcopter fitted with a digital camera. Tests were first conducted to determine if sound from the UAV altered feeding behavior. A second experiment was conducted to determine if UAV video monitoring could be used to predict intake of known amounts of food. Number and length of visits to feeders were monitored for each cow in both experiments and correlated with amount of food eaten. No effect of sound on intake was detected. Strong positive correlations were observed between feeding frequency observations from UAV video footage analysis and actual amount of food consumed from each feeder. However, battery length limited observations to approximately five minutes per flight. Further development of UAV power sources is needed to provide greater flight autonomy for use of this tool in rangeland environments.

}, url = {files/bibliography/16-015.pdf}, author = {S. Nyamuryekung{\textquoteright}e and Andr{\'e}s F. Cibils and Richard E. Estell and Amy L. Gonzalez} } @article {JRN54649, title = {Use of an unmanned aerial vehicle-mounted video camera to assess feeding behavior of Raramuri Criollo cows}, journal = {Rangeland Ecology and Management}, volume = {69}, year = {2016}, month = {09/2016}, pages = {386-389}, abstract = {

We determined the feasibility of using unmanned aerial vehicle (UAV) video monitoring to predict intake of discrete food items of rangeland-raised Raramuri Criollo non-nursing beef cows. Thirty-five cows were released into a 405-m2 rectangular dry lot, either in pairs (pilot tests) or individually (experiment tests), that contained 12 food bowls arranged in an open semicircle and placed approximately 1 m apart. Four bowls containing either long alfalfa hay (AH, 200 g), long Sudangrass hay (SH, 200 g), or cottonseed cake (CC, 50 g) were alternated (CC, AH, SH) using the same sequence in all tests. Video footage of all arena tests was acquired with a three-dimensional Robotics Y6 Multi-copter fitted with a two-axis brushless gimbal and a GoPro Hero 3 Silver Digital Camera. Video files were processed to extract a total of 4893 two-second-interval still images that were viewed to determine cow feeding activity. Cows that were na{\"\i}ve to the sound of the UAV fed as frequently (P \> 0.05) as their adapted counterparts during 12-min pilot tests. Significant positive correlations (r = 0.68-0.91; P \< 0.05) between video-derived feeding frequency estimates and amount of AH, SH, and CC consumed per bowl were observed during the individual 4-min experiment tests. Our results suggest that UAV video monitoring could be a useful tool to monitor feeding behavior of rangeland cows.

}, doi = {http://dx.doi.org/10.1016/j.rama.2016.04.005}, url = {files/bibliography/16-022.pdf}, author = {S. Nyamuryekung{\textquoteright}e and Andr{\'e}s F. Cibils and Richard E. Estell and Amy L. Gonzalez} } @article {JRN54607, title = {Using albedo to reform wind erosion modelling, mapping and monitoring}, journal = {Aeolian Research}, volume = {23}, year = {2016}, month = {12/2016}, chapter = {63}, abstract = {
Dust emission models are used to assess the impacts of dust on radiative forcing in the atmosphere, cloud formation, nutrient fertilisation and human health. We describe a need in aeolian research to adequately represent the spatial variability and particularly the area average of the key aerodynamic properties which influence these models and our understanding of the processes. The models are underpinned by a two-dimensional geometric property (lateral cover; L) used to characterise the three-dimensional aerodynamic roughness (sheltered area or wakes) of the Earth{\textquoteright}s surface and calibrate the momentum it extracts from the wind. We reveal a fundamental weakness in L and its latent influence on roughness configuration and demonstrate that significant aerodynamic interactions between roughness elements and their sheltered areas have been omitted particularly under sparse surface roughness (0.001\<L\<0.1). We describe a solution which develops earlier work to establish a relation between sheltered area and the proportion of shadow over a given area; the inverse of direct beam directional hemispherical reflectance (black sky albedo; BSA). We show direct relations between shadow and wind tunnel measurements and thereby provide direct calibrations of key aerodynamic properties. Estimation of the aerodynamic parameters from albedo enables wind erosion assessments over areas across platforms from the field to airborne and readily available data from satellite remote sensing. The approach also demonstrated redundancy in existing wind erosion models and thereby reduced their complexity but improved fidelity. We found that the use of albedo enabled an adequate description of aerodynamic sheltering to characterise drag partition and predict sediment transport without the use of a drag partition scheme and the entrainment threshold. We applied the calibrations to produce global maps of aerodynamic properties which showed very similar spatial patterns to each other and confirmed the redundancy in the traditional approach to wind erosion modelling. The global maps identified regions of small aerodynamic roughness previously thought to be susceptible to wind erosion because of their erodibility. We evaluated temporal patterns of predicted horizontal mass flux at locations across Australia which revealed variation between land cover types that would not be detected using traditional models. The work shows how this new approach provides new opportunities to investigate the dynamics of wind erosion in space and time and elucidate aeolian processes across scales.
}, doi = {http://dx.doi.org/10.1016/j.aeolia.2016.09.006}, url = {files/bibliography/16-030.pdf}, author = {Nicholas Webb and A. Chappell} } @conference {JRN54446, title = {Using JournalMap to improve discovery and visualization of rangeland scientific knowledge}, booktitle = {68th Annual Society for Range Management Meeting}, year = {2015}, month = {02/2015}, publisher = {Sociiety for Range Management}, organization = {Sociiety for Range Management}, address = {Sacramento, CA}, abstract = {

Most of the ecological research conducted around the world is tied to specific places; however, that location information is locked up in the text and figures of scientific articles in myriad forms that are not easily searchable. While access to ecological literature has improved dramatically in the digital age, the ability to find out what is known about a specific place is hindered by current search technologies that still rely primarily on key word, topic, text, and author searching. Tools for discovering and evaluating ecological studies have largely focused on the what of research while downplaying the where. This is somewhat surprising given the strong spatial focus of ecology and the growing number of powerful map-based search and analysis tools that are readily available. To address these needs we created JournalMap (http:// www.journalmap.org), a map-based scientific literature database and search engine. With JournalMap we use study area descriptions from the article to map where the research was actually conducted. We demonstrate the value of mapbased knowledge discovery with three examples: a time-series visualization of sage-grouse (Centrocercus urophasianus) knowledge from over 300 articles, an assessment of the omission and commission errors associated with topical searching for articles within the Chihuahuan Desert, and mapping patterns and biases of rangeland research knowledge from over 1,500 articles fromRangeland Ecology and Management and the Journal of Arid Environments. These three examples illustrate how map-based search engines can improve knowledge discovery and reveal gaps in ecological knowledge. JournalMap{\textquoteright}s goal is to encourage the science community to improve location reporting in peer-reviewed literature and increase the discoverability of relevant scientific knowledge through web mapping interfaces.

}, author = {Jeffrey K. Gillan and Jason W. Karl and Galera, Ashley} } @conference {JRN54452, title = {Using soils and land potential as a basis for land use decisions and conservation planning: A resilience-based strategy}, booktitle = {100th Annual Meeting of the Ecological Society of America}, year = {2015}, month = {08/2015}, publisher = {Ecological Society of America}, organization = {Ecological Society of America}, address = {Baltimore, MD}, abstract = {

Land use decisions are becoming increasingly complex and contentious as demands for food, fiber, energy and infrastructure expand. Recent definitions of {\textquotedblleft}planetary boundaries{\textquotedblright} and arbitrary land use limits circumscribing the {\textquotedblleft}Safe Operating Space{\textquotedblright} for humans are helpful in drawing attention to global resource constraints, but fail to recognize that some uses of some types of land result in relatively irreversible changes to the land potential, while others sustain or even restore the capacity of the land to provide a diverse ecosystem services in the future.\  This paper describes a resilience-based strategy for using soils to sustain long-term land potential, while increasing the supply of land-requiring products and services. This strategy includes five elements. Each of the elements is based on a simple definition of soil resilience: soil is assumed to be resilient to a particular land use if its capacity to support the currently possible range ecosystem services can be restored within a human generation solely through vegetation management. Land uses are generally resilient if they do not result in modification of the relatively static properties of the soil profile, including texture, depth and mineralogy. Most (but not all) soils, for example, are resilient to soil organic matter losses provided that near-surface soil texture is not modified through erosion or deposition. (1) Identify land already dominated by human use where {\textquotedblleft}ecosystem service gaps{\textquotedblright} exist by constraining the definition of {\textquotedblleft}gap{\textquotedblright} to the difference between current yields and the highest yield achievable without a loss of land potential.\  (2) Identify land where current land use is unsustainable. (3) Carefully match land use and management with land potential, ensuring the maximum sustainable benefit is achieved from each hectare of land. (4) Promote development of new management systems and technologies designed to sustainably exceed current potential. (5) Promote innovation by facilitating more rapid knowledge and information sharing among individuals managing similar types of land. The paper concludes with a brief overview of several new reports and tools, including mobile apps, designed to help land use planners, conservation planners and land managers better match land use with land potential.\  OOS 31-5.

}, author = {Jeffrey E. Herrick} } @conference {JRN54447, title = {Using the best available data: integrating field data and remote sensing imagery to monitor rangelands}, booktitle = {68th Annual Society for Range Management Meeting}, year = {2015}, month = {02/2015}, publisher = {Sociiety for Range Management}, organization = {Sociiety for Range Management}, address = {Sacramento, CA}, abstract = {

Monitoring of rangelands poses significant challenges to land managers due to broad extent and many uses of rangelands. The Bureau of Land Management{\textquoteright}s (BLM) Assessment, Inventory, and Monitoring (AIM) program seeks to efficiently collect standard, quantitative monitoring data which is collected once and used multiple times to address a range of management questions. However, the cost of collecting field data to sufficiently monitor landscapes can be prohibitive. Remote sensing image classification provides an opportunity to derive rangeland indicators over large areas and at more frequent intervals than field data collection campaigns. We demonstrate a hierarchical Bayesian approach for maximizing the efficiency of monitoring data collection where existing AIM field plots are used to a) train remote sensing image classification and b) provide finer resolution data in areas of management concern. Where available, high spatial resolution images (e.g., RapidEye) are classified and the results of this classification are used together with field data to improve the moderate spatial resolution image (e.g., Landsat OLS) classification. Results of our classification of 2.7 million acres in northern California show remote sensing-derived estimates of bare ground, shrub cover, and herbaceous cover are the most accurate but other indicators, such as soil aggregate stability, plant density, and vegetation species composition, are best estimated using field collected data. Utilizing AIM field data together with remote sensing enables a strategic rangeland monitoring approach where field data meet multiple monitoring objectives. Combining multiple types of data improves estimates of indicators thus providing higher quality monitoring data to rangeland managers.

}, author = {Sarah McCord and Jason W. Karl} } @conference {JRN54399, title = {USDA Southwest climate hub for climate change}, booktitle = {Climate Prediction Applications Science Workshop (CPASW)}, year = {2015}, month = {03/2015}, publisher = {Climate Prediction Applications Science Workshop (CPASW)}, organization = {Climate Prediction Applications Science Workshop (CPASW)}, address = {Las Cruces, NM}, abstract = {

The USDA Southwest (SW) Climate Hub was created in February 2014 to develop risk adaptation and mitigation strategies for coping with climate change effects on agricultural productivity. There are seven regional hubs across the country with three subsidiary hubs. The SW Climate Hub Region is made up of six states: New Mexico, Arizona, Utah, Nevada, California and Hawaii (plus the Trust Territories of the Pacific Islands). The SW Climate Hub has a subsidiary hub located in Davis, California. The Southwest region has high climatic diversity, with the lowest and highest average annual rainfall in the U.S.(6.0 cm in Death Valley, CA and 1168 cm at Mt. Waialeale, HI). There are major deserts in five of the six states, yet most of the states, with exception of Hawaii, depend upon the melting of mountain snowpacks for their surface water supply. Additionally, many of the agricultural areas of the SW Regional Hub depend upon irrigation water to maintain productivity. The SW Regional Hub will rely upon existing infrastructure of the Cooperative Extension Service at Land-Grant State Universities. Extension service and USDA-NRCS personnel have existing networks to communicate with stakeholders (farmers, ranchers, and forest landowners) through meetings and workshops which have already started in the six states. Outreach through the development of a weather and climate impact modules designed for seventh grade students and their teachers will foster education of future generations of rural land managers. We will be synthesizing and evaluating existing reports, literature and information on regional climate projections, water resources, and agricultural adaptation strategies related to climate in the Southwest. The results will be organized in a spatial format and provided through the SW Hub website (http://swclimatehub.info) and peer-reviewed articles.

}, author = {A. Rango and Caitriana Steele and Emile H. Elias and Kris Havstad} } @proceedings {JRN54117, title = {Using goats and sheep to control juniper saplings: what we{\textquoteright}ve learned}, year = {2014}, month = {07/2014}, pages = {11-12}, publisher = {New Mexico State University}, address = {Corona, NM}, abstract = {

The primary findings and conclusions were synthesized from a series of papers published between 2006-2014 from studies conducted at CRLRC and the NMSU Campus Farm seeking to determine the feasibility of using sheep and goats to suppress oneseed juniper sapling encroachment. We found that protein supplements and polyethylene glycol (PEG) can be used to boost juniper intake of goats and sheep (especially goats) in all seasons except fall. Co-grazing of sheep and goats (approximately 50\% of each) at high stocking density was the grazing prescription that achieved highest juniper sapling utilization. Browsing of small saplings was most frequent in summer, whereas debarking of branches on taller saplings was the most common impact in spring. Browsing-induced sapling mortality was approximately 5\%; however, branch mortality due to debarking ranged from 13-22\%. We observed no adverse effects of this grazing treatment on understory herbaceous vegetation.

}, url = {/files/bibliography/14-031.pdf}, author = {Andr{\'e}s F. Cibils and S. A. Utsumi and Richard E. Estell} } @conference {JRN54397, title = {USDA southwest regional hub for adaptation to and mitigation of climate change}, booktitle = {American Geophysical Union Fall Meeting 2014}, year = {2014}, month = {12/2014}, publisher = {AGU}, organization = {AGU}, address = {San Francisco, CA}, abstract = {

The USDA Southwest (SW) Climate Hub was created in February 2014 to develop risk adaptation and mitigation strategies for coping with climate change effects on agricultural productivity.\  There are seven regional hubs across the country with three subsidiary hubs.\  The SW Climate Hub Region is made up of six states:\  New Mexico, Arizona, Utah, Nevada, California and Hawaii (plus the Trust Territories of the Pacific Islands).\ \  The SW Climate Hub has a subsidiary hub located in Davis, California because of the large agricultural productivity, wide variety of crops, and the high value of many of the crops.\  The Southwest region has a high climatic diversity.\  The lowest average r=annual rainfall (6.0 cm) and highest temperature recorded (57o C) in the U.S were located in Death Valley, CA.\  The highest average annual rainfall in the U.S. is located in Mt. Waialeale, Hawaii with 1169 cm.\  The lowest temperature recorded in the Region was in Peter{\textquoteright}s Sink, UT with -56oC.\  Despite the fact that there are major deserts in four of the six states, most of the states, with exception of Hawaii, depend upon the melting of mountain snowpacks for their surface water supply.\  Additionally, many of the productive agricultural areas of the SW Regional Hub depend upon irrigation water for this high productivity.

}, author = {A. Rango and Emile H. Elias and Caitriana Steele and Kris Havstad} } @article {JRN53960, title = {Using Spatial Statistics and Point-Pattern Simulations to Assess the Spatial Dependency Between Greater Sage-Grouse and Anthropogenic Features}, journal = {Wildlife Society Bulletin}, volume = {37}, year = {2013}, month = {05/2013}, pages = {301-310}, chapter = {301}, abstract = {

The greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to the loss of habitat is the expanding human population with associated development and infrastructure. Our objective was to use a spatial-statistical approach to assess the effect of roads, power transmission lines, and rural buildings on sage-grouse habitat use. We used the pair correlation function (PCF) spatial statistic to compare sage-grouse radiotelemetry locations in west-central Idaho, USA, to the locations of anthropogenic features to determine whether sage-grouse avoided these features, thus reducing available habitat. To determine significance, we compared empirical PCFs with Monte Carlo simulations that replicated the spatial autocorrelation of the sampled sage-grouse locations. We demonstrate the implications of selecting an appropriate null model for the spatial statistical analysis by comparing results using a spatially random and a clustered null model. Results indicated that sage-grouse avoided buildings by 150 m and power transmission lines by 600 m, because their PCFs were outside the bounds of a 95\% significance envelope constructed from 1,000 iterations of a null model. Sage-grouse exhibited no detectable avoidance of major and minor roads. The methods used here are broadly applicable in conservation biology and wildlife management to evaluate spatial relationships between species occurrence and landscape features. Our results can directly inform planning of infrastructure and other development projects in or near sage-grouse habitat.

}, keywords = {Centrocercus urophasianus, Monte Carlo, pair correlation function, point pattern, Ripley{\textquoteright}s K, sage-grouse, spatial statistics}, doi = {10.1002/wsb.272}, url = {/files/bibliography/13-037.pdf}, author = {Jeffrey K. Gillan and Strand, Eva K. and Jason W. Karl and Reese, Kerry P. and Laninga, Tamara} } @article {JRN53930, title = {Using very-large-scale aerial imagery for rangeland monitoring and assessment: some statistical considerations}, journal = {Rangeland Ecology and Management}, volume = {65}, year = {2012}, month = {07/01/2012}, pages = {330-339}, chapter = {330}, abstract = {

The availability of very-high-resolution (VHR) imagery and techniques for processing those data into indicators of ecosystem function has opened the door for VHR imagery to be used in rangeland monitoring and assessment. However, VHR imagery can be expensive and, like any survey measurement, studies that rely on VHR-image-based indicators will be subject survey errors that lead to biased results or inflated standard errors. To yield defensible monitoring and assessment data for managers, indicators derived from VHR imagery must be implemented with a statistically valid sampling design. We discuss the use of VHR imagery from the perspectives of achieving unbiased estimates with minimal survey errors in the context of rangeland monitoring and assessment. Our discussion includes study design considerations such as the importance of probability-based sampling for generating credible estimates; measurement errors in VHR-derived indicators; and model-assisted estimation to integrate data from multiple sources, improve precision and adjust for sources of errors. We demonstrate the effects of these design considerations using example datasets where VHR imagery and concurrent field data were collected. Finally, we propose practical ways to conduct statistically-sound rangeland monitoring and assessment using VHR imagery.

}, keywords = {accuracy, monitoring, precision, sample design, statistics, very-large-scale aerial image}, doi = {10.2111/REM-D-11-00102.1}, url = {/files/bibliography/12-041.pdf}, author = {Jason W. Karl and Danielle Duni and Nusser, Sarah and Opsomer, Jean and Unnasch, Robert S.} } @proceedings {JRN54590, title = {Using time-series intervention analysis to model cow heart rate affected by programmed audio and environmental/physiological}, volume = {CDROM}, year = {2011}, month = {05/2011}, publisher = {Applied Statistics In Agriculture Conference}, address = {Manhattan, KS}, abstract = {This research is the first use of the Box-Jenkins time-series models to describe changes in heart rate (HR) of free-ranging crossbred cows (Bos taurus) receiving both programmed audio cues from directional virtual fencing (DVFTM) devices and non-programmed environmental/physiological cues. The DVFTM device is designed to control the animal{\textquoteright}s location on the landscape. Polar Accurex{\textregistered} devices were used to capture HR every minute between 19 and 24 March 2003, when three mature free-ranging beef cows, previously habituated to the DVFTM device, were confined to a brush-infested area of an arid rangeland paddock. Global positioning system (GPS) electronics were used to record each cow{\textquoteright}s location approximately every minute while it was in a 58 ha virtual paddock (VPTM) and every second when it penetrated a virtual boundary (VBTM). The cows never escaped through the VBTM, although they penetrated it a total of 26 times in 11 different events, at which times they received programmed audio cues lasting from 1 to 56 s. Plots of these data reveal that HR spikes from programmed audio cues all fell within textbook range for cow HR (40-186 beats per minute, bpm). Heart rate spikes were analyzed using Box-Jenkins intervention analysis models, which showed that for both audio and selected environmental/physiological events, HR spikes typically returned to pre-cuing "baseline" levels in about one minute. However, the longest return-time to baseline (about four minutes) was for an environmental/physiological event of unknown origin. HR, animal location, weather and other electronic data should be measured at equally-spaced time intervals using a single time stamp to accurately associate HR changes with possible causes.}, author = {D.M. Anderson and N. Remenyi and L. W. Murray} } @conference {49952, title = {Utilizing the tropic interactions of nematodes as indicators of change in soil biota associated with the loss of bouteloua eiopda grasslands}, booktitle = {96th Ecological Society of America Meeting}, year = {2011}, month = {08/2011}, publisher = {ESA}, organization = {ESA}, address = {Austin, Texas}, abstract = {Conversion of perennial grasslands to shrublands is a desertification process that is important globally. Changes in aboveground ecosystem properties with this conversion have been well-documented, but little is known about how belowground communities are affected, yet these belowground communities may be important constraints on the reversal of this state change. We examined nematode community structure and feeding as a proxy for soil biotic change across a desertification gradient in southern NM, USA. We had two objectives: (1) to compare nematode trophic structure and species diversity within vegetation states representing different stages of desertification and (2) to compare nematode community structure between bare and vegetated patches because research has shown that semi-arid grasslands are highly connected via a matrix of endophytic fungi and soil biotic crusts that link vegetated and bare ground patches. The gradient included a perennial grassland dominated by Bouteloua eriopoda, the historic dominant in the Chihuahuan Desert, a duneland dominated by the native invasive shrub, Prosopis glandulosa, and the ecotone between them. We also sampled a relatively undisturbed, ungrazed B. eriopoda grassland at a nearby site to serve as an end member of our gradient.\  Nematode communities were sampled using soil cores to depth of 15 cm at each location in 2009 and 2010. Results showed that grasslands and mesquite dunelands had different trophic groupings; herbivorous nematode communities with lower species diversity and evenness occurred in both ends of our established gradient compared with the ecotone. Nematode communities had significantly greater numbers in 2009 than 2010 in the duneland.\  Herbivorous nematodes were found in greater numbers in 2009 than 2010 in the ecotone. Nematode trophic structure and herbivore communities were significantly different from all vegetation states with the highest observed diversity in the undisturbed, ungrazed B. eriopoda grassland sampled in 2010. Vegetated and bare ground patches within the two grassland sites had similar herbivore communities, especially species from the family Tylenchinae. However, dunes in the mesquite dunelande areas had significantly larger nematode abundance than interdune areas where bacteriavores dominated, mediating N transformations and possibly perpetuating the \“islands of fertility\” found in dunelands.\  Decreased nematode trophic structure and species diversity in the Jornada samples compared with the undisturbed grassland illustrate the effect of desertification on the soil biotic community. Our results show that nematodes can be used to identify changes in belowground community structure based on trophic interactions. Large-scale disturbances like desertification can have consequences on the diversity and soil biotic functioning at finer spatial scales.}, author = {Jeremy R. Klass and Trojan, Jacqueline M. and S. Thomas and Debra C. Peters} } @article {49955, title = {UAS remote sensing missions for rangeland applications}, journal = {Geocarto International}, volume = {26}, year = {2011}, month = {03/01/2011}, pages = {141-156}, chapter = {141}, abstract = {Rangelands cover about 50\% of the earth{\textquoteright}s land surface, are in remote areas and have low population densities, all of which provide an ideal opportunity for remote sensing applications from unmanned aircraft systems (UAS). In this paper, we describe a proven workflow for UAS-based remote sensing, and discuss geometric errors of image mosaics and classification accuracies at different levels of detail. We report on several UAS missions over rangelands in Idaho and New Mexico, USA, where we acquired 6-8-cm resolution aerial photography and concurrent field measurements. The geometric accuracies of the image mosaics were in the 1-2 m range, and overall classification accuracies for vegetation maps ranged from 78\% to 92\%. Despite current FAA regulations that restrict UAS operations to distances within line-of-sight of the UAS, our results show that UAS are a viable platform for obtaining very high resolution remote sensing products for applied vegetation mapping of rangelands.}, keywords = {digital camera, photogrammetry, rangelands, UAS, unmanned aircraft systems}, doi = {10.1080/10106049.2010.534557}, url = {/files/bibliography/11-002.pdf}, author = {Andrea S. Laliberte and Craig Winters and A. Rango} } @proceedings {JRN54523, title = {Using the snowmelt runoff model to evaluate climate change effects and to compare basin runoff between New Mexico and Idaho.}, volume = {Abstract $\#$7481. p. 17}, year = {2011}, month = {11/2011}, publisher = {American Water Resources Association Conference }, address = {Albuquerque, New Mexico}, abstract = {The Snowmelt Runoff Model(SRM) has been developed and tested in small to large basins worldwide. SRM has been found to be very useful for understanding snowmelt processes as well as for simulating or forecasting snowmelt-derived water supplies. SRM is being used in New Mexico in a NSF-funded EPSCoR(Experimental Program to Stimulate Competitive Research) project. All important snowmelt sub basins of the Rio Grande in New Mexico and Colorado are being studied to provide required snow covered area inputs to SRM in and attempt to answer what the climate change impacts on New Mexico{\textquoteright}s mountain sources of water are. Landsat and MODIS satellites are being employed to remotely sense snow cover in both New Mexico and Colorado. Initial mapping provided information that indicated that resolution better than provided by MODIS(250-500m) would be necessary, so we have used Landsat(15-30m) when available. Additionally, it seemed that the satellite mapping was not detecting all the snow cover in the forest snow zone. The forest cover was delineated with high resolution, but much less frequent aerial photography. The addition of these approaches provides better hydrologic simulations without resorting to changes in the SRM parameters. SRM has a further advantage for evaluating climate change effects on water supply because it has an algorithm that automatically takes any future climate scenario into account. Such future climates are being derived from climate models run over the Rio Grande basin. Various snowmelt algorithms in SRM are being used independently in Idaho basins driven by another important snow variable: the daily snow water equivalent available from NRCS SNOTEL sites. It is important to compare the output of basins in the northern Rockies(Idaho) to those in the southern Rockies(New Mexico/Colorado). Typically, a La Nina year like 2011 in Idaho produces above average snow accumulation and runoff whereas in New Mexico or Colorado, La Nina produces well below average snowpacks and runoff. SRM snowmelt calculations can be made using either snow covered area or snow water equivalent inputs. This presentation will show examples of each of these SRM-related products.}, author = {A. Rango and Caitriana Steele and Demouche, Leann and J. Martinec and Abramovich, Ron} } @article {49985, title = {The utilization of historical data and geospatial technology advances at the Jornada Experimental Range to support western America ranching culture}, journal = {Remote Sensing}, volume = {3}, year = {2011}, month = {09/2011}, pages = {2089-2109}, chapter = {2089}, abstract = {By the early 1900s, concerns were expressed by ranchers, academicians, and federal scientists that widespread overgrazing and invasion of native grassland by woody shrubs were having severe negative impacts upon normal grazing practices in Western America. Ranchers wanted to reverse these trends and continue their way of life and were willing to work with scientists to achieve these goals. One response to this desire was establishment of the USDA Jornada Experimental Range (783 km2) in south central New Mexico by a Presidential Executive Order in 1912 for conducting rangeland investigations. This cooperative effort involved experiments to understand principles of proper management and the processes causing the woody shrub invasion as well as to identify treatments to eradicate shrubs. By the late 1940s, it was apparent that combining the historical ground-based data accumulated at Jornada Experimental Range with rapidly expanding post World War II technologies would yield a better understanding of the driving processes in these arid and semiarid ecosystems which could then lead to improved rangeland management practices. One specific technology was the use of aerial photography to interpret landscape resource conditions. The assembly and utilization of long-term historical aerial photography data sets has occurred over the last half century. More recently, Global Positioning System (GPS) techniques have been used in a myriad of scientific endeavors including efforts to accurately locate historical and contemporary treatment plots and to track research animals including livestock and wildlife. As an incredible amount of both spatial and temporal data became available, Geographic Information Systems have been exploited to display various layers of data over the same locations. Subsequent analyses of these data layers have begun to yield new insights. The most recent technological development has been the deployment of Unmanned Aerial Vehicles (UAVs) that afford the opportunity to obtain high (5 cm) resolution data now required for rangeland monitoring. The Jornada team is now a leader in civil UAV applications in the USA. The scientific advances at the Jornada in fields such as remote sensing can be traced to the original Western America ranching culture that established the Jornada in 1912 and which persists as an important influence in shaping research directions today.}, keywords = {geospatial technology, historical data, remote sensing, Unmanned Aerial Vehicles, Western American culture}, doi = {10.3390/rs3092089}, url = {/files/bibliography/11-031.pdf}, author = {A. Rango and Kris Havstad and Richard E. Estell} } @proceedings {49917, title = {Using time-series intervention analysis to model cow heart rate affected by programmed audio and environmental/physiological cues}, year = {2010}, note = {Original journal Applied Animal Behavior (rejected) - change to Physiology \& Behavior10/12/2007 resbumitted to Livestock Science}, month = {2010}, pages = {107-136}, publisher = {Kansas State University}, address = {Manhattan, Kansas}, abstract = {

This research is the first attempt at using time -series analysis to describe changes in the heart rate (HR) of free-ranging cows receiving programmed audio cues from directional virtual fencing (DVF\™) devices designed to control the animal\&$\#$39;s location on the landscape as well as non-programmed environmental/physiological cues. Polar Accurex\® devices were used to capture HR every minute between March 19-24, 2003 when three mature free-ranging beef cows previously habituated to DVF\™ control were confined to a brush-infested area of an arid rangeland paddock. Global positioning system (GPS)electronics were used to locate each cow\&$\#$39;s location approximately every minute while it was in a 58 ha virtual paddock (VP\™) and every second when it penetrated a virtual boundary (VB\™). The cows never escaped through the VB\™ though they penetrated it a total of 26 times in 11 different events at which time they received programmed audio cues lasting from 1 to 56 s. These data reveal that HR spikes from programmed audio cues all fell within the textbook range for cow HR (40-186 beats per minute, bpm). For both audio and selected evironmental /physiological events, HR spikes returned to pre-cuing \"baseline\" values in about one minute. However, the longest return time to baseline lasted (about 4 minutes) and this was for an environmental/physiological event. HR, animal location, weather and other electronic data should be measured at equally-spaced time intervals using a single time stamp so as to accurately associate HR changes with possible causes.

}, keywords = {audio cue, direction virtual fencing, DVM, free-ranging beef cattle, heart rate, Polar hear rate monitors, time-series analysis}, url = {/files/bibliography/10-045.pdf}, author = {D.M. Anderson and N. Remenyi and L. W. Murray} } @conference {JRN54491, title = {Using object-based image analysis to guide the selection of field sample locations}, booktitle = {GEOBIA 2010}, year = {2010}, month = {06/2010}, publisher = {GEOBIA}, organization = {GEOBIA}, address = {Ghent, Belgium}, abstract = {One of the most challenging tasks for resource management and research is designing field sampling schemes to achieve unbiased estimates of ecosystem parameters as efficiently as possible. This study focused on the potential of fine-scale image objects from object-based image analysis (OBIA) to be used as sampling units. If image objects represent homogeneous areas on the ground with respect to sampling objectives, then their use as sampling units may have the potential to decrease sample variances, increase efficiency, and incorporate landscape information for sampling proportional to objectives while achieving unbiased estimates of rangeland parameters. We evaluated the use of image objects to define sampling units for measuring percent cover of plants in a southern Idaho sagebrush (Atremisia spp.) ecosystem. Using a fine-scale segmentation of an IKONOS image, we selected 24 pairs of adjacent image objects that spanned a range from very similar to very different with respect to the spectral mean and standard deviation of each object in the pair. In the field, 10 downward-looking photos were taken at random locations within each object (20 per pair). Percent cover of five functional groups was calculated from each photo, and mean and variance of percent cover was calculated for each object in the pair and for the pair as a whole (i.e., ignoring the boundary between the two objects). We found that variances in percent cover measurements were lower for individual objects than for object pairs. Additionally, we found that the mean in percent cover between adjacent image objects increased with the spectral difference between objects. These results suggest that objects derived from OBIA can be used as sampling units and that placing sample sites within objects can help avoid sampling across ecological boundaries.}, author = {Jason W. Karl and MacFarlane, David W.} } @conference {50041, title = {Unmanned aerial vehicles for hyperspatial remote sensing of rangelands: object-based classification and field validation}, booktitle = {American Society for Photogrammetry and Remote Sensing (ASPRS) Annual Meeting}, year = {2010}, month = {April 26-30, 201}, address = {San Diego, CA}, abstract = {UAVs are ideally suited for monitoring and assessing vegetation conditions in remote rangelands due to the relatively low operating costs, ability for fast deployment, and greater flexibility than piloted aircraft. The likelihood of obtaining FAA permission for operating a UAV is also greater in remote and unpopulated rangeland areas. Researchers at the Jornada Experimental Range have been investigating rangeland remote sensing applications with UAVs for several years, are acquiring UAV imagery on a regular basis, and have developed reliable techniques for deriving hyperspatial UAV image mosaics. However, several challenges remain. While the spatial resolution of the imagery is high (6-8 cm GSD), the spectral and radiometric resolution is low due to the low-cost digital camera used on the UAV. Field validation is also complicated due to the relatively large error of conventional GPS-collected field data in relation to the very high spatial resolution imagery. In this study, we used object-based image analysis (OBIA) techniques and tested field data collections suitable for object-based classification of hyperspatial UAV imagery. The UAV image mosaic was segmented and classified into broad land cover classes, and the segmentation outlines were used in the field as a base for collecting training samples to fine-tune the classification to the species level. The training samples were used as input for a decision tree analysis, which incorporated spectral, spatial, contextual and texture features. The digital data collection allowed for an easy transfer into the image analysis software. Results indicate that geometric and classification accuracies are suitable for routine rangeland monitoring purposes, and that unmanned aircraft are a viable tool for obtaining very high resolution vegetation maps. The field data acquisition methods in conjunction with OBIA are also applicable to very high resolution digital aerial imagery acquired with piloted aircraft. }, author = {Andrea S. Laliberte and A. Rango and Craig Winters and A. L. Slaughter and Connie J. Maxwell} } @article {50049, title = {Using hydrogel filled, embedded tubes to sustain grass transplants for arid land restoration}, journal = {Journal of Arid Enviornments}, volume = {74}, year = {2010}, pages = {987-990}, abstract = {

Grass restoration on remote arid rangelands may require irrigation to stimulate establishment. However, irrigation on undeveloped sites is costly. Vertical irrigation tubes that direct applied moisture to subsurface zones where evaporation is reduced, and hydrogels that prevent applied moisture from infiltrating beyond plant root zones can maximize the portion of applied water available for plant uptake.\  The survival and growth of Bouteloua eriopoda (Torr.) Torr. transplants irrigated with either starch- or acrylic-based hydrogels contained in one of three embedded watering tube styles were evaluated in a greenhouse trial. A field trial evaluated differences in transplant survival and cover between treatments consisting of embedded watering tubes with or without acrylic hydrogels. Greenhouse transplants from all treatments grew 146 days on less than 1 L of water. Plants irrigated with starch hydrogels consumed the most water and exhibited the most growth. Variations in tube styles had minor effects on plant growth and water loss from tubes. In the field, heavy growing season precipitation was observed, and transplant survival was high for both treatments. No significant differences in cover were detected.\  Greenhouse data demonstrate potential for hydrogel filled, embedded tubes to provide adequate moisture for establishment and growth of deep-rooted black grama transplants. Field data indicate deep-rooted black grama transplants establish successfully when adequate moisture is available.

}, keywords = {black grama, remote site irrigation, soil moiste}, url = {/files/bibliography/10-05.pdf}, author = {M.E. Lucero and Dreesen, D.R. and D. VanLeeuwen} } @conference {50114, title = {UAS-derived imagery and terrain models for rangeland mapping and monitoring}, booktitle = {Unmanned Vehicle Systems (UVS) Canada Conference}, year = {2009}, month = {11/2/2009}, address = {Victoria, BC, Canada}, abstract = {

Images from satellites and piloted aircraft have been used extensively for mapping and monitoring rangelands, which comprise approximately 50\% of the world\’s land area. Unmanned aircraft systems (UAS) are ideally suited for monitoring these vast and remote areas, and derived data can bridge the gap between coarser resolution imagery and ground-based information. Small UAS (\<50 kg) offer the advantage of low operating costs, fast and repeated deployment, and low flying heights resulting in very high resolution imagery. However, image processing approaches require adaptation or customization to handle the large number of small-footprint images, account for low accuracy GPS/IMU data, and classify images from low-cost sensors into quality vegetation maps. We are presenting a proven workflow for orthorectification, mosaicking, and classification of 6 cm resolution UAS imagery acquired with a low-cost digital camera. The geometric accuracies of orthorectified image mosaics comprised of 200-300 images were in the 1-2 m range. Classification accuracies for rangeland vegetation maps ranged from 78\%-92\%, depending on number of classes. Digital surface models (DSM) extracted from the imagery can be used to estimate parameters for hydrologic and erosion models. Dense DSMs extracted at the pixel level have potential for deriving vegetation heights. A multispectral sensor acquiring 10-bit data in 6 narrow bands ranging from blue to near infrared is currently undergoing testing. Current FAA regulations in the U.S. limit the potential for widespread UAS image acquisition missions, but the image processing and analysis methods developed on smaller areas are scalable to larger areas.

}, author = {Andrea S. Laliberte and A. Rango} } @conference {50112, title = {Unmanned aircraft mission for rangeland remote sensing applications in the US national airspace}, booktitle = {Unmanned Vehicle Systems (UVS) Canada Conference}, year = {2009}, month = {11/02/2009}, address = {Victoria, BC, Canada}, abstract = {In recent years, civilian applications of unmanned aerial systems (UAS) have increased considerably due to their greater availability and the miniaturization of sensors, GPS, inertial measurement units, and other hardware. UAS are well suited for rangeland remote sensing applications, because of the remoteness and low population density of rangelands, and the need of land management agencies for monitoring and assessing these areas, a task that is not feasible with ground monitoring techniques alone. While UAS offer reduced operational costs, faster deployment, and more flexibility than piloted aircraft, the operator also has to conform to the Federal Aviation Administration{\textquoteright}s (FAA) regulations on operating a UAS in the National Airspace, limiting the area and altitude of the UAS mission. We report here on 1) our experiences in operating a UAS under Certificates of Authorization for the purpose of image acquisition for rangeland monitoring, 2) on the UAS missions, and 3) on image processing and analysis for vegetation mapping. We acquired 6-cm resolution true color aerial photography over rangelands in southern New Mexico and southwestern Idaho. Concurrently, field measurements of vegetation were collected. The imagery was orthorectified, mosaicked, and analyzed using object-based image analysis. Geometric and classification accuracies were sufficient for rangeland monitoring and assessment purposes, and allowed for mapping the structure and patterns of vegetation and soil in great detail. The results show that in spite of the current constraints of FAA regulations, UAS are a viable tool for rangeland monitoring.}, author = {Andrea S. Laliberte} } @article {50137, title = {Unmanned aerial vehicle-based remote sensing for rangeland assessment, monitoring, and management}, journal = {Journal of Applied Remote Sensing}, volume = {3}, year = {2009}, month = {08/2009}, pages = {033542}, abstract = {

Rangeland comprises as much as 70\% of the Earth\’s land surface area. Much of this vast space is in very remote areas that are expensive and often impossible to access on the ground. Unmanned Aerial Vehicles (UAVs) have great potential for rangeland management. UAVs have several advantages over satellites and piloted aircraft: they can be deployed quickly and repeatedly; they are less costly and safer than piloted aircraft; they are flexible in terms of flying height and timing of missions; and they can obtain imagery at sub-decimeter resolution. This hyperspatial imagery allows for quantification of plant cover, composition, and structure at multiple spatial scales. Our experiments have shown that this capability, from an off-the-shelf mini-UAV, is directly applicable to operational agency needs for measuring and monitoring. For use by operational agencies to carry out their mandated responsibilities, various requirements must be met: an affordable and reliable platform; a capability for autonomous, low altitude flights; takeoff and landing in small areas surrounded by rugged terrain; and an easily applied data analysis methodology. A number of image processing and orthorectification challenges have been or are currently being addressed, but the potential to depict the land surface commensurate with field data perspectives across broader spatial extents is unrivaled.

}, keywords = {aerial photography, autonomous flight, indicators, rangeland applications, Small unmanned aerial vehicles}, doi = {10.1117/1.3216822}, url = {/files/bibliography/09-025.pdf}, author = {A. Rango and Andrea S. Laliberte and Jeffrey E. Herrick and Craig Winters and Kris Havstad and Caitriana Steele and Dawn M. Browning} } @conference {50306, title = {Understanding global warming impacts to forest and rangeland landscapes with benchmark ecological sites}, booktitle = {Geological Society of America}, year = {2008}, month = {October 5-9, 200}, pages = {766-1}, address = {Houston, TX}, abstract = {A benchmark ecological site is one that has the greatest potential to yield data and information about ecological functions, processes, and the effects of management or climate change that can apply to a broad area or critical ecological zone. A benchmark ecological site represents other similar sites in a major land resource area (MLRA). Information gathered about benchmark ecological sites can address many different ecological, social, and resource management issues. One of the purposes of designating benchmark ecological sites is to promote greater understanding of the potential impacts of global climate change on rangeland and forest ecosystem dynamics and soils. Measures of ecosystem change against reliable benchmarks will allow land managers to use adaptive management to provide for sustainability of natural resources on these landscapes. Examples of resource issues that could be addressed include impacts of climate change and management actions on threatened, endangered, and other plant and animal species of concern; soil erosion, sedimentation, and runoff; soil ecology; plant community composition and productivity; and habitat reclamation potential.}, keywords = {ecological sites, global warming}, author = {Ypsilantis, W. and Michael S. Karl and Bottomley, T. and Biggam, P. and A. O{\textquoteright}Green and Townsend, L. and Brandon T Bestelmeyer and Davis, R. and Gilgert, W. and Dibenedetto, J. and Renthal, J.} } @article {50317, title = {Upscaling understanding of nitrogen dynamics associated with overland flow in a semi-arid environment}, journal = {Biogeochemistry}, volume = {82}, number = {3}, year = {2007}, note = {//Walnut Gulch//LTER-V//entered 08/14/2007; updated 05/14/2008}, month = {2007}, pages = {265-278}, abstract = {

An experiment was designed to further the empirical understanding of the effects of scale on fluxes of water and dissolved nitrogen from hillslopes in semi-arid shrubland. It was hypothesised that the behaviour of dissolved nitrogen is related to the scale of the contributing hillslope/catchment area and dynamics of the overland flow as has been demonstrated to be the case for soil erosion (Parsons et al. 2006). Data from four hillslope scales (ca. 21300 m2) and one subcatchment (ca. 1,500 m2), collected over two monsoon seasons, support this hypothesis and demonstrate that the key controls of average dissolved nitrogen yields are flow discharge and plot scale. The slope of the best-fit line describing the relationship between flow discharge and total dissolved nitrogen (TDN) yields descreases with increasing scale, from 0.0183 at 21.01 m2, 0.0092 at 56.84 m2, 0.0059 at 115.94 m2, 0.0024 at 302.19 m2 to 0.0004 at 1,500 m2. An implication of these findings is that care must be taken when upscaling results describing nutrient behaviour from small, plot experiments, as this behaviour appears to be scale dependent. For example, average yields of TDN in overland flow increase to a maximum with increasing plot area until an area of 50 m2 is reached, and decline with increasing plot size thereafter. Thus, studies that rely upon fixed plot scales may misrepresent catchment- or landscape-scale fluxes as they do not describe the changing relationship between overland flow and nutrient fluxes with increasing spatial scale. Further investigations into intra-event behaviour illustrate that nitrogen losses from natural rainfall/runoff events are supply limited as over the course of the events monitored, decreasing concentrations illustrate a pattern of nutrient exhaustion. When events are compared at the same sites through the monsoon season, however, the anticipated seasonal exhaustion effect is not present. This work provides an empirical basis to upscale the understanding of dissolved nitrogen behaviour from small hillslope plots to catchment scales in degraded semi-arid environments.

}, keywords = {article, hydrology, nitrogen yields, hydrology, overland flow, hydrology, soil erosion, journal, nitrogen, hydrology, scale, soil erosion, hydrology}, doi = {10.1007/s10533-007-9070-x}, url = {files/bibliography/JRN00487.pdf}, author = {Richard E. Brazier and A.J. Parsons and John Wainwright and Mark D. Powell and W. H. Schlesinger} } @conference {50334, title = {Using the GIS to study the past and present of a northern Chihuahuan Desert playa}, booktitle = {60th Annual Meeting and Trade Show, Society for Range Management}, year = {2007}, month = {02/09/2007}, pages = {Paper No. 179}, address = {Sparks/Reno, NV}, abstract = {The encroachment of mesquite (Prosopis glandulosa Torr.) and other desert shrubs into the desert grasslands of the northern Chihuahuan Desert is commonly associated with increased rates of soil erosion. The processes associated with vegetation shifts are still poorly understood. One such example of vegetation shift is the replacement of tobosa (Pleuraphis mutica Buckely) grasslands by mesquite dunelands on the Red Lake playa, an ephemeral lake on the USDA-ARS Jornada Experimental Range in south central New Mexico, USA. The objective of this project was to describe grass-shrubland transitions for vegetation patches based on soil characteristics and spatial context. We used aerial photos from 1942 and 1973 and a digital orthophoto quarter quadrangle from 1996 to define changes in the mesquite-dominated area since 1942. We used the 1996 photos to compare GIS-based mesquite canopy intercept measurements with line-point and canopy intercept measurements completed in 2005. We then used a QuickBird satellite image from 2004 to identify current vegetation community patches based on vegetation type, soil reflectance, and the spatial distribution of plants and bare ground within each patch. Plots were then established in the field within these patches to characterize the soils and vegetation of the site and create highly-detailed soil and vegetation maps of the site. After the initial characterization, the field data and 2004 satellite image were compared against the older imagery and past vegetation and soil maps to identify areas requiring more intensive soil and vegetation measurements. We plan to use these data to identify relationships between various soil properties and vegetation community composition and structure. This information will be used on patterns and processes to propose changes to state-and-trainsition models correlated with soils in this area.}, keywords = {Chihuahuan Desert, GIS, mesquite, soil erosion}, author = {N.K. Hansen and Jeffrey E. Herrick and Laurie Abbott and Debra C. Peters and D. Parker} } @proceedings {50354, title = {Unmanned aerial vehicles for rangeland mapping and monitoring: a comparison of two systems}, year = {2007}, month = {05/2007}, pages = {CDROM}, address = {Tampa, FL}, abstract = {Aerial photography from unmanned aerial vehicles (UAVs) bridges the gap between ground-based observations and remotely sensed imagery from aerial and satellite platforms. UAVs can be deployed quickly and repeatedly, are less costly and safer than piloted aircraft, and can obtain very high-resolution imagery. At the Jornada Experimental Range in New Mexico, ongoing research is aimed at determining the utility of UAVs for rangeland mapping and monitoring. Digital images of arid rangelands were acquired with two UAVs that differed in size/weight, payload capacity, flight duration, GPS guidance capability and cost. The first system was a modified model airplane equipped with GPS and able to fly along preloaded waypoints and acquire images with a digital camera. The second UAV was a BAT 3 (MLB Systems) with fully autonomous flight capability and equipped with color video and digital cameras. Both units provide a data file containing GPS and elevation for each image, but the BAT also records roll, pitch and yaw data. Both systems acquired high quality, high-resolution images of approximately 5 cm ground resolution (150 m flying height). Because the images have a small footprint (152 m x 114 m), mosaicking is required for further image analysis. Inclusion of camera calibration parameters (lens distortion, focal length, principal point) greatly increased the accuracy of the aero triangulation and resulting orthophotos. Due to the greater stability of the BAT and its longer flight range, the BAT imagery is better suited for analysis of larger areas than the imagery from the model airplane. However, the model airplane offers comparable image resolution and a cost effective alternative to the larger and more expensive UAV systems. Details of both systems, image acquisition and image processing results are discussed and compared.}, keywords = {aerial, monitoring, UAV, unmanned, vehicles}, url = {/files/bibliography/07-033.pdf}, author = {Andrea S. Laliberte and A. Rango and Jeffrey E. Herrick} } @article {50405, title = {Use of fluorometry to differentiate among clipped species in the Genera, Astragalus, Oxytropis and Pleuraphis}, journal = {Rangeland Ecology and Management}, volume = {59}, year = {2006}, month = {September 2006}, pages = {557-563}, abstract = {A rapid and reproducible method to determine botanical composition of forage is an ecological and economic goal for range animal ecologists. Multidimensional fluorometry previously demonstrated the possibility of a unique optical approach for accurately determining species composition of pre- and post-digested plant materials. Fluorometry may be used to detect toxic plants in standing crop as well as diets by using electronic transitions in chemical structures at wavelengths between 370 and 580 nm. Grass hay (genus Pleuraphis) and six clipped forbs (four species of Astragalus and two species of Oxytropis) were examined. The resulting spectral signatures were evaluated for differences in the blue and green regions of the visible spectrum using Principle Component Analysis (PCA). This represents the first published data using chemometrics to differentiate among fluorophores from these plant extracts. It was possible to distinguish between the grass and forbs and among forbs. Further research will be required to evaluate these same plant species in mixed diets and fecal samples. http://www.srmjournals.org/archive/1551-5028/59/5/pdf/i1551-5028-59-5-557.pdf}, keywords = {astragalus, botanical composition, fluorescence spectroscopy, fluorometry, genera, oxytropis, pleuraphis, poisonous plants, Principal Component Analysis (PCA)}, url = {/files/bibliography/06-036.pdf}, author = {D.M. Anderson and G.D. Rayson and S. Obeidat and M. Ralphs and Richard E. Estell and E.L. Fredrickson and E. Parker and Gray, P.} } @article {50441, title = {Use of low-temperature scanning electron Microscopy to compare and characterize three classes of snow cover}, journal = {Scanning}, volume = {28}, year = {2006}, month = {12/2006}, pages = {191-203}, abstract = {

This study, which uses low temperature scanning electron microscopy (LTSEM), systematically sampled and characterized snow crystals that were collected from three unique classes of snow cover: prairie, taiga and alpine. These classes, which were defined in previous field studies, result from exposure to unique climatic variables relating to wind, precipitation and air temperature. Snow samples were taken at 10 cm depth intervals from the walls of freshly excavated snow pits. The depth of the snow pits for the prairie, taiga and alpine covers were 28 cm, 81 cm and 110 cm, respectively. Visual examination revealed that the prairie snow cover consisted of two distinct layers whereas the taiga and alpine covers had four distinct layers. Visual measurements were able to establish the range of crystal sizes that occurred in each layer, the temperature within the pit and the snow density. The LTSEM observations revealed the detailed structures of the types of crystals that occurred in the snow covers and documented the metamorphosis that transpired in the descending layers. Briefly, the top layers from two of the snow covers, consisted of freshly fallen snow crystals that could be readily distinguished as plates and columns (prairie) or graupel (taiga). Alternatively, the top layer in the alpine cover consisted of older dendritic crystal fragments that had undergone early metamorphosis, i.e. they had lost their sharp edges and had begun to show signs of joining or bonding with neighboring crystals. A unique layer, known as sun crust, was found in the prairie snow cover; however, successive samplings from all three snow covers showed similar stages of metamorphism that led to the formation of depth hoar crystals. These changes included the gradual development of large, three-dimensional crystals having clearly defined flat faces, sharp edges, internal depressions and facets. The study, which indicates that LTSEM can be used to enhance visual data by systematically characterizing snow crystals that are collected at remote locations, is important for understanding the physics of snowpacks and the metamorphosis that leads to potential avalanche situations. In addition, the metamorphosis of snow crystals must be considered when microwave radiometry is used to estimate the snow water equivalent in the winter snowpack, because large snow crystals more effectively scatter passive microwave radiation than small crystals. http://http://www3.interscience.wiley.com/cgi-bin/fulltext/113509454/PDFSTART

}, keywords = {depth hoar, low temperature scanning electron, snow cover, snow crystal}, url = {/files/bibliography/07-020.pdf}, author = {J. Foster and R. Kelly and A. Rango and Armstrong, R. and E. R. Erbe and C.D. Pooley and W.P. Wergin} } @inbook {50475, title = {Understanding global desertification: biophysical and socioeconomic dimensions of hydrology}, booktitle = {Dryland Ecohydrology}, year = {2006}, month = {January 2006}, pages = {315-332}, publisher = {Springer}, organization = {Springer}, address = {The Netherlands}, abstract = {This chapter reviews some of the key concerns and challenges associated with dryland desertification, emphasizing the role of hydrological processes. Hydrological processes are a function of complex interactions and linkages between specific patch types and landscape units; and thus, one of the keys to understanding both the causes and consequences of land degradation. Degradation involves a reduction in the ability of the land to support one or more functions. The interpretation of change as "loss" is dependent upon the context of the socioeconomic activities of human beings. The chapter ends with a discussion of future directions, including the development of the Dahlem Desertification Paradigm (DDP), a new approach to desertification designed to facilitate directed research effort and progress.}, keywords = {biophysical, desertification, hydrology, socioeconomic}, url = {/files/bibliography/06-050.pdf}, author = {F. Maestre and J. F. Reynolds and E. Huber-Sannwald and Jeffrey E. Herrick and Stafford-Smith, M.} } @conference {50491, title = {Use of gene specific primers to identify fungal endophytes of native grasses}, booktitle = {Research Insights in Semiarid Ecosystems Symposium}, year = {2006}, abstract = {

Both abiotic and biotic factors impact the plant populations of semiarid and arid ecosystems. As we learn more about how microbial populations within these ecological communities impact plant lifecycles, it becomes apparent that preservation and restoration of native plant communities might in part rely on establishing or reestablishing the microbial inhabitants of native plants. Fungi play a crucial role in many ecological processes. Despite this, fungal diversity and function within natural habitats are poorly defined. Within native grasses, fungal endophytes are ubiquitous, suggesting mutualistic or symbiotic relationships that might strengthen the ability of these grasses to survive under adverse conditions. We are interested in the plant-microbe(s) interactions that are present in the native grass Bouteloua eriopoda, (black grama), in a rangeland environment, and are using fungal specific oligonucleotide primers and polymerase chain reaction (PCR) to help identify fungal endophytes that closely associate with this grass. Our interest is to characterize the extent of the plant-fungal interaction and to study the persistence of specific fungi across the B. eriopoda community.

}, keywords = {abiotic, biotic, endophytes, fungal, grass, native}, author = {Potenza, C.L. and A. L. Slaughter and I. Reyes-Vera and Ruth L. Sedillo and M.E. Lucero and J.R. Barrow} } @article {50494, title = {Using unmanned aerial vehicles for rangelands: Current applications and future potentials}, journal = {Environmental Practice}, volume = {8}, number = {(3)}, year = {2006}, month = {September 1, 200}, pages = {159-168}, abstract = {

High resolution aerial photographs have important rangeland applications such as monitoring vegetation change, developing grazing strategies, determining rangeland health, and assessing remediation treatment effectiveness. Acquisition of high resolution images by Unmanned Aerial Vehicles (UAVs) has certain advantages over piloted aircraft missions including lower cost, improved safety, flexibility in mission planning, and closer proximity to the target. Different levels of remote sensing data can be combined to provide more comprehensive information: 15-30m resolution imaging from space-borne sensors for determining uniform landscape units; \<1m satellite or aircraft data to assess the pattern of ecological states in an area of interest; 5cm UAV images to measure gap and patch sizes as well as percent bare soil and vegetation ground cover; and \<1cm ground-based boom photography for ground truth or reference data. Two parallel tracks of investigation are necessary: one which emphasizes the utilization of the most technically advanced sensors for research and a second which emphasizes minimizing costs and maximizing simplicity for monitoring purposes. We envisage that in the future, resource management agencies, rangeland consultants, and private land managers should be able to use small, lightweight UAVs to satisfy their need for acquiring improved data at a reasonable cost and for making appropriate management decisions.

}, keywords = {high resoluiton, photographs, rangeland applications, remediation treatment, UAV}, doi = {10.1017/S1466046606060224}, url = {/files/bibliography/06-039.pdf}, author = {A. Rango and Andrea S. Laliberte and Caitriana Steele and Jeffrey E. Herrick and Brandon T Bestelmeyer and T. J. Schmugge and Roanhorse, A. and Jenkins, V.} } @conference {50530, title = {Understanding Interactions Between Autonomous Animal Control and Temperament When Cattle are Subejcted to Virtual Fencing Applications}, booktitle = {Horizons in Livestock Sciences Conference}, year = {2005}, month = {October 2-5, 200}, pages = {23}, address = {Queensland, Australia}, abstract = {Virtual fencing has the potential to control grazing livestock. Understanding and refining the cues that can alter behavior is an integral part of autonomous animal control. A series of tests have been completed to explore the relationship between temperament and control. Prior to exposure to virtual fencing control the animals were scored for temperament using flight speed and a sociability index using contact logging devices. The behavioural response of 30, Belmont Red steers were observed for behavioural changes when presented with cues prior to receiving an electrical stimulation. A control and four treatments designed to interrupt the animal{\textquoteright}s movement down an alley were tested. The treatments consisted of sound plus electrical stimulation, vibration plus electrical stimulation, a visual cue plus electrical stimulation and electrical stimulation by itself. The treatments were randomly applied to each animal over five consecutive trials. A control treatment in which no cues were applied was used to establish a basal behavioural pattern. A trial was considered completed after each animal had been retained behind the cue barrier for at least 60 sec. All cues and electrical stimulation were manually applied from a laptop located on a portable 3.5 m tower located immediately outside the alley. The electrical stimulation consisted of 1.0 Kv of electricity. Electric stimulation, sound, and vibration along with the Global Position System (GPS) hardware to autonomously record the animal{\textquoteright}s path within the alley were recorded every second.}, keywords = {animal control, controls, temperament, virtual fencing}, author = {D.M. Anderson} } @conference {50527, title = {Using animal behavior and electronics to controll free-ranging animal groups directional virtual fencing (DVM) - Proof-of-concept}, booktitle = {2005 Horizons in Livestock Sciences Conference}, year = {2005}, month = {2005}, abstract = {Improved animal distribution promotes ecologically sound landscape utilization. Diverse utilization patterns require active management of timing and duration of foraging. After 30 years of research, a patented methodology to reintroduce the art of low-stress herding husbandry using 21st century science awaits commercialization. Directional Virtual Fencing (DVF\™) melds cutting edge electronics with innate animal behaviors to control free-ranging animals without visible fences. The system compares an animal\’s location using Global Positioning System (GPS) technology to a Virtual Center Line (VCL\™) after the VCL\™ location has been programmed into the device\’s Geographic Information System (GIS). A magnetometer in the DVF\™ device determines the animal\’s angle of approach to the nearest VCL\™. Bilateral ramped audio and electric stimulation cues increase in irritation intensity as an animal approaches the VCL\™ within a Virtual Boundary (VB\™). Cuing stops immediately once the animal turns away from the VCL\™. The type of cue, length of cuing and the side of the animal to which the cue is applied are all programmable. This flexibility offers the DVF\™ user many options to implement Prescription Stocking (RxS\™). The first autonomous field test of DVF\™ occurred on April 2, 2001. Since then, our team has determined that DVF\™ can control animal groups behind static as well as moving VBs\™. Current research is focused on developing power efficient hardware with a small footprint coupled to wireless data transmission capabilities in a potentially patentable solar powered head mounted device. With DVF\™ the art of animal husbandry is integrated with cutting edge technology.}, keywords = {behavior, Directional, electronics, fencing, free-ranging, virtual}, author = {D.M. Anderson and C.S. Hale and B. Nolen and Kris Havstad} } @article {50591, title = {Using historic data to assess effectiveness of shrub removal in southern New Mexico}, journal = {Journal of Arid Environments}, volume = {62}, number = {1}, year = {2005}, month = {July 1, 2005}, pages = {75-91}, abstract = {

In the late 1930{\textquoteright}s, the presence of a highly organized labor force, the Civilian Conservation Corps (CCC), in the Jornada Basin of southern New Mexico provided the capability for rangeland scientists to conduct experiments to determine the effectiveness of various techniques for remediating or reversing the encroachment of shrubs into grasslands. Unfortunately, soon after the treatments were performed, the CCC disbanded and most records of the treatments were lost. Despite sketchy documentation, some rangeland treatments left legacies on the landscape, and effects on water retention, erosion, and vegetation dynamics remained long after the CCC work ended. The discovery of historical documents from long-closed files and aerial photography in widely scattered archives allowed some of the experiments to be located and reexamined. Two research areas established in the mid-1930s were of particular interest, namely a tarbush (Flourensia cernua) site where shrubs were grubbed and quadrats established and a creosote (Larrea tridentata) site where both creosote and tarbush shrubs were grubbed. Here we outline how these sites were rediscovered, how historical measurements were repeated for the first time since the late l930s, and conclusions drawn regarding specific rangeland remediation strategies and vegetation dynamics. Our results show that shrub populations recovered from a radical removal treatment in less than 65 years. Remediation of these sites so that grass will recover to pre-shrub-dominated amounts will require measures additional to just removal of shrubs in order to restore hydrologic function. The fact that we were able to relocate, revisit, and resample these treatment areas provided unique opportunities to understand the long-term vegetation dynamics of these arid ecosystems. It is evident that woody plant populations have a high degree of resilience, that density dependence or interference appears to limit plant size in arid shrub communities, and that shrub populations had not reached any stable equilibrium state at the time of treatment in the 1930s. These insights would have been impossible to gain from short-term studies and without long-term studies initiated in the 1930s combined with recent discoveries of original documentation and historical aerial photography. http://authors.elsevier.com/sd/article/S0140196304002411

}, keywords = {aerial, grasslands, historical, photography, remediation, shrubs}, doi = {10.1016/j.jaridenv.2004.11.001}, url = {/files/bibliography/05-002.pdf}, author = {A. Rango and L. Huenneke and M. Buonopane and Jeffrey E. Herrick and Kris Havstad} } @conference {50613, title = {Use of Goats for the Control of Salt Cedar}, year = {2005}, month = {January 9, 2005}, address = {Sevilleta, NM}, abstract = {Fire, flood, herbicide, manual, mechanical and insect biocontrol methods have all been used to remove invasive salt cedar. Each method has advantages and disadvantages in particular circumstances. We used goats to browse replicated 1-3 acre plots in salt cedar near San Acacia and San Marcial along the Rio Grande. Goats damaged nearly all the salt cedar in the browsed areas. The width of salt cedars was decreased by 33\% -36\% in mixed vegetation. In areas where salt cedar was removed mechanically, then allowed to regrow for 4 years, goats reduced the LAI by about 37\%. Goat browsing was less effective in dense stands of large salt cedar, with LAI decreased by about 27\%. The number of salt cedar decreased by only 4\% after the second year of treatment. It may take more than 5 years to kill individual salt cedars with repeated goat browsing. Goats browsed desirable native plants as well as salt cedar, but most of the vegetation recovered during the following growing season.}, keywords = {goats, salt cedar, Sevilleta}, author = {S. Tartowski} } @booklet {50614, title = {Use of Goats to Control Salt Cedar}, howpublished = {The Nature Park News}, volume = {14}, number = {2}, year = {2005}, month = {May 15, 2005}, pages = {3}, publisher = {Chihuahuan Desert Nature Park}, address = {Las Cruces, NM}, abstract = {Invasive Salt Cedar (Tamarix spp.) occupies riparian zones throughout the Western United States and has been reported to increase evapotranspiration, increase fire frequency, reduce habitat values, and replace native plant species. Herbicides and mechanical clearing are the main methods used to remove salt cedar. We are conducting the first study of the use of goats to control salt cedar. Goats readily browsed salt cedar and Russian olive in replicated 1-3 acre plots along the Rio Grande, while maintaining weight and health. Nearly every salt cedar plant was damaged by browsing, breaking branches or stripping bark. Goats had an especially severe impact on resprouts, removing about half of the vegetation in the first year of browsing. Goats had much less impact on large dense salt cedar , but cleared out the understory, reducing laddering fuels, improving access for recreation and reducing costs for mechanical or manual clearing. After two years of goat treatment, the width of salt cedars was reduced by about 35\%, but only about 4\% of the large salt cedars were killed. It may take five years of goat browsing to deplete the root reserves of salt cedar sufficiently to increase tree mortality. Goats browsed desirable native plants as well as salt cedar, but most of the understory vegetation recovered during the following growing season. Large cottonwoods were not damaged and browsed willows resprouted vigorously. Grass cover, especially native grama grasses (Bouteloua barbatus and B. aristoides), increased from less than 1\% immediately before goat browsing to about 20\% one year after goat browsing.}, keywords = {goats, salt cedar}, author = {S. Tartowski} } @article {50693, title = {Understanding an ecological system: an example of temporal and spatial variability of Dorymyrmex (Conomyrma) insana in a stressed system}, journal = {Journal of Animal and Veterinary Advances}, volume = {3}, number = {9}, year = {2004}, month = {September 1, 200}, pages = {631-637}, abstract = {The responses of pyramid ants Dorymyrmex (Conomyrma) insana (Buckley) to structural change (removal of an invasive shrub species) and to an environmental stress (short-term, intense grazing by cattle) are presented from an experiment study in Chihuahuan Desert grassland. Spatial and temporal responses of D. insana were examined by analysis of variances, kriging maps, and regression analyses. There were no significant responses of D. insana to grazing. The numerical and spatial responses of ants recorded from pitfall trap data were the same as those recorded from mapping ant nests. The spatial distribution of D. insana nests was a function of the canopy cover of the invasive, woody shrub, honey mesquite (Fabaceae: Prosopis glandulosa Torrey) (r = 0.82) and explained 68\% of the variability in nest distribution. The dominant, liquid-feeding ant species (D. insana) responded numerically and spatially to structural change and environmental stress. Spatially referenced data are as important or more important for monitoring ecosystem change than are numerical data.}, keywords = {ANOVA, ants, biological indicator, grazing, kriging, mesquite shrub, multiple stressor, spatial and temporal variability}, url = {/files/bibliography/04-002.pdf}, author = {M. S. Nash and Walter G. Whitford} } @conference {50740, title = {Unique characteristics of a systemic fungal endophyte of native grasses and shrubs in arid southwestern rangelands}, booktitle = {Wildland Shrub Symposium}, year = {2003}, month = {January 8, 2003}, pages = {6}, abstract = {Native grasses and shrubs in arid southwestern rangelands are more extensively colonized by dark septate endophytic fungi than by traditional mycorrhizal fungi. A histochemical method was developed that revealed active internal structures that have not been observed using conventional protocol for fungal analysis. These fungi nonpathogenically and totally colonize all sieve elements, cortical and epidermal cells. They grow inter and intracellulary forming an intimate integrated association with all root cells. Their internal morphology is often atypical of commonly recognized symbiotic or pathogenic fungal colonization. These endophytes accumulate and disperse large quantities of lipids through the root. They form a mucilage layer on the root surface which protects the root and maintains hydraulic continuity with dry soil. Our results suggest that these fungi function as carbon managers and enhance nutrient and water uptake in arid ecosystems.}, author = {J.R. Barrow} } @conference {50743, title = {Using state-and-transition models: Tools for prophylaxis, diagnosis, or autopsy?}, booktitle = {56th Annual Meeting of Society for Range Management}, year = {2003}, month = {February 1, 2003}, pages = {16}, address = {Casper, Wyoming}, abstract = {As range managers and ecologists proceed with creating state-and-transition models, it is important to ask how they can be used to maintain rangeland health. We explore this question by examining how the Bureau of Land Management has used models, and by considering field studies of transitions in New Mexico. Models are often used in a {\textquoteright}post-mortem{\textquoteright} fashion to explain the existence of degraded states. It is difficult, however, to identify the ultimate causes of degradation. Another challenge is to identify indicators in models that can be used to alert managers to the initial stages of degradation and to guide management changes. This difficulty is illustrated by cases in which healthy-looking landscapes degrade without continued human impacts. In other cases, landscapes that exhibit clear warnings of an impending transition recover without grazing adjustments. A promising use of state-and-transition models is to illustrate how within- and among site variability in topography and inherent soil properties (e.g. texture and depth) predispose sites to transitions. In this application, emphasis is placed on the relative risks of an undesired transition associated with landscape position, soil properties and regional climate characteristics. Unrecorded, unpredictable, and interacting variables (such as climate and species introductions) restrict our ability to correctly interpret and predict transitions. Nonetheless, state-and-transition models provide a basis for prediction, management action, and tests of concepts. We will discuss research approaches to addressing the various uses of state-and-transition models.}, author = {Brandon T Bestelmeyer and Joel R. Brown and Jeffrey E. Herrick and Phil Smith and Kris Havstad} } @conference {50804, title = {Understanding vegetation dynamics provides insights to sustainable invasive plant management and remediation strategies}, booktitle = {7th International Conference on the Ecology and Management of Alien Plant Invasions (ESA/WSSA Joint Meeting)}, year = {2003}, month = {November 3-7, 20}, pages = {68}, address = {Fort Lauderdale, FL}, abstract = {Our objective is to provide insights into the management of invasive species and remediation of native ecosystems using a combination of long-term studies of vegetation dynamics, short-term process-based experiments, and integrative simulation models. Throughout the western US, encroachment by native woody species into perennial grasslands has been occurring over the past 100 to 200 years. Permanent plots located at long-term research stations have documented this invasion process since the early 1900{\textquoteright}s. Recent analyses of these long-term data show high spatial variability in shrub invasion rates and grass persistence at the landscape scale. This high spatial variability in grass/shrub interactions and dynamics led to short-term experiments to identify the key processes influencing grass persistence on some sites and inability of grasses to recover on others. A simulation model that integrates key biotic processes and abiotic drivers was used to predict the sites most sensitive or responsive to remediation efforts and those sites most resistant to change. Thus, remediation strategies based on an integration of long-term observations, results from short-term experiments, and simulation model analyses have a greater probability of success than a single approach. These tools are also useful in improving our understanding and management of invasive species.}, author = {Debra C. Peters and Kris Havstad and Jin Yao} } @article {50812, title = {The utility of historical aerial photographs for detecting and judging the effectiveness of rangeland remediation treatments}, journal = {Environmental Practice}, volume = {5}, number = {2}, year = {2003}, month = {June 1, 2003}, pages = {107-118}, abstract = {

Aerial photos are a type of remote sensing data especially valuable for rangeland applications. This type of data has advantages that include relative ease of interpretation and acquisition, inexpensiveness, high resolution (1-2m), and providing a common reference for communication among those involved in rangeland management. Additionally, air photos are especially well suited for analysis of historical rangeland remediation treatments because acquisition of widespread aerial photographic coverage began during the 1930{\textquoteright}s. Several types of treatments are easily identified and monitored over time, including contour terraces, brush water spreaders, rootplow seeding, water ponding dikes, shrub removal by grubbing, and grazing restrictions. The use of aerial photos allows us the opportunity to recreate the management history of rangeland and to serve as a point of departure for involvement in more sophisticated satellite-based remote sensing systems.

}, keywords = {aerial photography, air photo archives, Civilian Conservation Corps, Jornada Basin, rangeland, remediation treatments, remote sensing}, doi = {10.1017/S1466046603031065}, url = {/files/bibliography/03-020.pdf}, author = {A. Rango and Kris Havstad} } @article {50814, title = {Using mechanistic models to scale ecological processes across space and time}, journal = {BioScience}, volume = {53}, number = {1}, year = {2003}, month = {January 1, 2003}, pages = {1-9}, abstract = {

Human activities affect the natural environment at local to global scales. To understand these effects, knowledge derived from short-term studies on small plots needs to be projected to much broader spatial and temporal scales. One way to project short-term, plot- scale knowledge to broader scales is to embed that knowledge in a mechanistic model of the ecosystem. The National Science Foundation{\textquoteright}s Long-Term Ecological Research (LTER) program makes two vital contributions to this type of modeling effort: (1) a commitment to multidisciplinary research at individual sites, which results in a broad range of mutually consistent data, and (2) long-term data sets essential for estimating rate constants for slower ecosystem processes that dominate long-term ecosystems dynamics. In this paper, we present four examples of how a mechanistic approach to modeling ecological processes can be used to make projections to broader scales. The models are all applied to sites in the LTER network.

}, keywords = {ecosystem moels, long-term ecological research, mechanistic models, scaling, spatial projection}, doi = {10.1641/0006-3568(2003)053[0068:UMMTSE]2.0.CO;2}, url = {/files/bibliography/03-008.pdf}, author = {E. B. Rastetter and Aber, J. D. and Debra C. Peters and Ojima, D.S. and Ingrid C. Burke} } @conference {50932, title = {Utilization of historic aerial photography to track long-term vegetation response to rangeland treatments}, booktitle = {87th Annual Meeting, Ecological Society of America}, year = {2002}, month = {August 4-9, 2002}, pages = {243}, address = {Tucson, AZ}, abstract = {During the past 100 years, semiarid grasslands in the Southwest have been heavily invaded by shrubs. To combat shrub invasion, a variety of rangeland remediation treatments have been conducted at the Jornada Experimental Range and the New Mexico State University Chihuahuan Desert Rangeland Research Center since the early 1900s; a maximum number of treatments were applied between 1933 and 1942, corresponding to the Civilian Conservation Corps (CCC) activities in southern New Mexico at that time. Despite the extensive nature of treatment application, very little detailed documentation remained on file after 1942 when the CCC was disbanded. We have had to rely on aerial photography missions started in the mid-1930s to document the extent, pattern, and persistence of the land cover treatments. The discovery of any remaining conventional file records of the treatments greatly increases our ability to interpret the aerial photography over the Jornada Basin. The persistence of visible treatments over time and changes in vegetation character in association with treatments allow assessment of treatment effectiveness. Supplemental vegetation measurements in these treatment (and control) areas today provide much information about ecosystem response and stability over time. Examples of aerial photography monitoring include: lagomorph, exclusion/shrub removal plots, cleared strips on creosote-dominated bajada slopes, snakeweed eradication plots, water ponding dikes for increasing forage growth, herbicide treatments in controlling mesquite, patterns of shrub invasion, and even discovery of totally undocumented remediation treatments in remote locations. The combination of aerial photography, historical data records, and current ground-based field measurements allows us to draw conclusions about long-term responses of vegetation communities which would not be possible with just one type of these data alone. The aerial photography interactive database for the Jornada Basin is under development and, currently, has over 3,000 images.}, author = {A. Rango and M. Buonopane and L. Huenneke and Kris Havstad and Connie J. Maxwell and Amy L. Gonzalez and Jeffrey E. Herrick} } @conference {50968, title = {Unique active internal morphology of dark septate fungal endophytes associated with roots of native grasses and shrubs in an arid ecosystem}, booktitle = {Third International Conference on Mycorrhizae}, year = {2001}, month = {July 8-13, 2001}, pages = {Abstract No. P1-69}, address = {Adelaide, Australia}, abstract = {Plants in arid ecosystems are exposed to severe nutrient and drought stress. Mycorrhizal fungi alleviate these stresses in natural ecosystems. Native grasses and shrubs in arid southwestern USA rangelands are more extensively colonized by dark septate fungal endophytes (DSE) than by conventional mycorrhizal fungi. The function of these endophytes is presently unresolved. Roots of grasses and shrubs native to the northern Chihuahuan Desert were stained with sudan IV, specific for lipids, and analyzed with high magnification differential interference microscopy. Unique, atypical extensions of DS fungi were observed that are not visible using fungus specific stains. Their prevalence in physiologically active roots suggested an active phase of DSE. Hyaline hyphae grew both inter- and intracellularly within the cortical cells and sieve elements and varied in visibility. Some hyphae had distinct hyaline walls, while others sin the sieve elements walls were evident only by positive staining of lipids in their vacuoles. These vacuoles were arranged in a typical linear and branched hyphae manner or they were highly irregular in shape. Large 5-8 um, lipid filled, hyphal vacuoles extended from the vascular cylinder through the cortex to the root surface which was coated with mucilage. The substantial lipid accumulation in hyphae extending from sieve elements to the root surface suggested that DSE fungi enhance rhizodeposition of carbon, the formation of a protective mucilage sheath that maintains hydraulic continuity and root function in dry soil.}, keywords = {dark septate, endophytes, fungal, internal morphology}, author = {J.R. Barrow and Aaltonen, R.E.} } @conference {51037, title = {Using Cesium-137 to understand landscape stability in the northern Chihuahuan Desert}, booktitle = {86th Annual Meeting, Ecological Society of America}, year = {2001}, month = {August 5-10, 200}, pages = {336}, address = {Madison, WI}, abstract = {An hypothesis for understanding the stability of the Northern Chihuahuan Desert landscapes is that the distribution of soil resources changes from spatially homogeneous in semiarid grasslands to heterogeneous in invading shrublands. Fallout Cesium-137 was deposited uniformly across the landscape during the 1950{\textquoteright}s and 1960{\textquoteright}s and was quickly adsorbed to soil particles, thus any redistribution of Cs-137 across the landscape would be due to soil redistribution. The concentration of fallout Cs-137 in soil profiles collected from different vegetation types (Grass, Mesquite, Tarbush, Tobosa) at the USDA-ARS Jornada Experimental Range in Northern Chihuahuan Desert in New Mexico was determined. At the Grass, Tarbush, and Tobosa sites, Cs-137 was uniformly distributed across the sites. At the Mesquite sites, Cs-137 was concentrated in the dune area under mesquite shrubs with little to no Cs-137 in the interdune areas. Cesium-137 data support the hypothesis that significant soil redistribution has occurred at the mesquite dune sites but at the Tarbush and Tobosa shrub sites the Cs-137 data do not support any major redistribution of soil resources. High concentrations of Cs-137 in the biological soil crust (0-5mm) at the Tarbush shrub sites indicate that biological soil crust contribute to the stability of these sites.}, author = {Jerry Ritchie and Jeffrey E. Herrick} } @conference {51064, title = {UV-induced fluorescence for the discernment of plant types from pre-and post-digested plant material}, booktitle = {27th Annual Meeting, Federation of Analytical Chemistry and Spectroscopy Societies}, year = {2000}, month = {September 2000}, pages = {Abstract p. 267}, address = {Nashville, TN}, abstract = {It has previously been determined that plant material fluoresces in two regions of the visible spectrum. The dominant chlorophyll fluorescence is found in the 600-800 nm region, while that, of yet unknown species, is observed in the 400-600 nm region. It was the goal of this study to determine if the blue-green fluorescence can act as a spectral signature for characterizing plant materials. The fluorescence spectra of samples o 3 plant forms, grasses, forbes and shrubs, have been studied. Utilizing the 400-600 nm region of the fluorescence spectrum, we were able to distinguish each of the three plant forms. Further studies on identifying plant species by this blue-green fluorescence will be described. With the aid of curve fitting programs and deconvolution methods, the emission spectra can supply information on the identity and contribution of the fluorescing compounds within the plant. The deconvolution and curve fitting of six plant species, Sporobolus flexuosus, Hilaria mutica, Dithyrea wislizeni, Sphaeralcea spp., Flourensia cernua, and Atriplex canescens, were performed. The results identified at least 4 emission bands within the 400-600 nm region. Within these bands, each plant species has a characteristic contribution. The application of this method to characterizing pre- and post-digested plant material will be discussed. The use of this technique to monitoring of feeding habits and dietary intake of free-ranging herbivores will also be discussed.}, keywords = {digested, plant material, plant types, UV-induced fluorescence}, author = {T.L. Danielson and G.D. Rayson and D.M. Anderson and Richard E. Estell and E.L. Fredrickson and Kris Havstad} } @conference {51145, title = {Using CENTURY to investigate ecosystem effects of a non-native species and implications for restoration}, booktitle = {84th Annual Meeting, Ecological Society of America}, volume = {80}, year = {1999}, month = {August 8-12, 199}, address = {Spokane, WA}, abstract = {Acroptilon repens (Russian knapweed), a non-native perennial composite, can form monospecific stands lasting decades on western rangeland. Biological control has limited success on A. repens expansion. Currently successful restoration efforts involve three key steps: herbicide application, soil cultivation, and seeding to grass. Cultivation is thought to release volatile allelochemicals trapped in the soil; however, cultivation can change many soil characteristics, including organic matter decomposition rates and nutrient availability. In order to simulate nitrogen cycles on paired rangeland plots dominated by either grass or A. repens, we used the CENTURY model with appropriately adjusted lignin:N and growth parameter values. CENTURY results suggest that net nitrogen mineralization is significantly reduced in soils under A. repens relative to soils under grass. After conversion from grass to A. repens domination, labile soil nitrogen pools decrease rapidly within the first couple of years, while slow soil nitrogen pools gradually increase for decades. Following chemical control and cultivation, the model predicts net nitrogen mineralization rates and labile soil nitrogen pools increase, in a pulse lasting a few years, to levels greater than that occurring in the paired grass-dominated rangeland. An empirical study is warranted to investigate whether the expected increase in nitrogen availability following cultivation is responsible for improved restoration success associated with cultivation, and if no-till restoration could be successful with nitrogen applications.}, author = {Fraleigh, H.D. and Debra C. Peters and Beck, K.G. and William Parton} } @article {51197, title = {Using resistance and resilience measurements for {\textquoteleft}fitness{\textquoteright} tests in ecosystem health}, journal = {Journal of Environmental Management}, volume = {57}, number = {1}, year = {1999}, month = {September 1, 199}, pages = {21-29}, abstract = {

The resistance and resilience of perennial grasses and a small shrub to a natural disturbance (drought) were measured on stress gradients that were produced by domestic livestock in desert grassland ecosystems in the northern Chihuahuan Desert of New Mexico, USA. Both survivorship of grasses and a sub-shrub (Gutierrezia sarothrae) during a drought (a measure of resistance) and re-establishment of plant cover following a drought (a measure of resilience) were reduced in the intensely stressed ecosystems in comparison to the lightly stressed ecosystems. The compromise of the resistance and resilience characteristics of an ecosystem can be used as a {\guillemotleft}fitness{\guillemotright} test for the health of ecosystems. Fitness tests can provide early warning of ecosystem degeneration and allow intervention to reduce or eliminate anthropogenic stress on the ecosystems.

}, keywords = {disturbance, ecosystem health, fitness test, grazing, resilience, resistance, stress, survivorship}, doi = {10.1006/jema.1999.0287}, url = {/files/bibliography/534.pdf}, author = {Walter G. Whitford and D. J. Rapport and A.G. de Soyza} } @proceedings {51234, title = {Utility of radiometric temperatures for surface energy flux estimation of a heterogeneous desert ecosystem}, year = {1998}, note = {//USDA//LTER III//ProCite field[6]: In}, month = {11-16 January 19}, pages = {67-72}, publisher = {American Meteorological Society}, address = {Phoenix, AZ}, abstract = {

Desert ecosystems contain sparse vegetation cover, which is randomly distributed over the landscape. In many cases where shrubs have invaded primarily grassland ecosystems, it has caused a marked change in vegetation structure and distribution resulting in significant changes in surface roughness and the spatial distribution of bare soil and vegetation. Use of standard bulk similarity formulations with radiometric temperature observations for estimating energy fluxes over heterogeneous, sparsely vegetated surfaces are shown to be generally unreliable. More recent efforts have been in developing formulations that accommodate differences between radiometric and aerodynamic temperatures, and hence would be more applicable to such heterogeneous surfaces. Two such models developed by Norman et al. (1995) and Chehbouni et al. (1996) are described in this paper, which have potential of being implemented operationally with satellite data. These models are applied to data collected during JORNEX (JORnada EXperiments) over a mesquite dune site in the USDA-ARS Jornada Experimental Range near Las Cruces, New Mexico. This site contains complex topography and heterogeneous cover where 0.5 m tall honey mesquite (Prosopis glandulosa Torr.) vegetation grow on dunes that are 1-2 m in height and 10{\textquoteright}s of meters in width. Very little if any vegetation exists in the interspace region.

}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, JORNEX, soil heat flux, model, radiometric temperatures, model, surface energy flux, proceeding, proceedings, radiometric temperature, model, radiometric temperature, surface energy flux, remote sensing, JORNEX, surface energy flux, model}, url = {/files/bibliography/Rango1998-01.pdf}, author = {William P. Kustas and J.H. Prueger and K. Ramalingam and T. J. Schmugge and A. Rango and Jerry Ritchie and Lawrence E. Hipps and J. Hatfield} } @proceedings {51327, title = {Using high temporal resolution satellite data to assess shrub control effectiveness}, volume = {General Technical Report INT-GTR-338}, year = {1996}, month = {May 23-25, 1995}, pages = {88-94}, publisher = {USDA Forest Service, Intermountain Research Station, Gen. Tech. Rep. INT-GTR-338}, address = {Las Cruces, NM}, abstract = {

Mapping vegetation through remotely sensed images involves various considerations, processes and techniques. Increasing availability of remotely sensed images due to the rapid advancement of remote sensing technology expands the horizon of our choices of imagery sources. Various sources of imagery are known for their differences in spectral, spatial, radioactive and temporal characteristics and thus are suitable for different purposes of vegetation mapping. Generally, it needs to develop a vegetation classification at first for classifying and mapping vegetation cover from remote sensed images either at a community level or species level. Then, correlations of the vegetation types (communities or species) within this classification system with discernible spectral characteristics of remote sensed imagery have to be identified. These spectral classes of the imagery are finally translated into the vegetation types in the image interpretation process, which is also called image processing. This paper presents an overview of how to use remote sensing imagery to classify and map vegetation cover.

}, keywords = {image classification, image processing, remote sensing sensors, vegetation mapping}, doi = {doi.org/10.1093/jpe/rtm005}, url = {/files/bibliography/478.pdf}, author = {M.D. Eve and Peters, A.J.}, editor = {J.R. Barrow and McArthur, E. Durant and R. E. Sosebee and R. J. Tausch} } @article {51349, title = {Using strontium and rubidium tracers to characterize nutrient uptake patterns in creosotebush and mesquite}, journal = {The Southwestern Naturalist}, volume = {41}, number = {3}, year = {1996}, note = {//NMSU//LTER III//}, month = {1996}, pages = {239-247}, abstract = {During the past 100 years, large areas of perennial grassland in the Chihuahuan Desert have been replaced by woody plants such as mesquite (Prosopis glandulosa) and creosotebush (Larrea tridentata). WE investigated the short-term pattern of resource acquisition by these two dominant desert shrubs during the summer in the Jornada del Muerto Basin, New Mexico. We hypothesized that for a given class of shrubs, nutrient uptake favors isolated plants and that larger plants have higher access to soil resources. We applied tracer solutions containing Sr and Rb (0.02 M each) to patches of soil located either beneath or beyond the canopy of isolated creosotebush and mesquite shrubs to examine the ability of these plants to acquire nutrients as a function of distance. Tracer solutions were also applied equidistant between paired shrubs to examine whether neighboring plants had equal access to soil resources. Mature foliage was analyzed for Sr and Rb at day 7, 21, and 35 after tracer application. Strontium and Rb in creosotebush increased steadily at a relative accumulation rate of 0.018 per day. Mesquite accumulation rates were lower, 0.013 per day for Sr and 0.002 per day for Rb. The highest Rb concentrations were found in small creosotebush and mesquite were not equal and these differences between neighboring shrubs could not be explained by variation in canopy volume. Creosotebush and mesquite had distinct uptake patterns for the two tracers indicating these species differ in surface root distribution and activity. Creosotebush appears to respond more rapidly to short-term increases in the availability of soil moisture and nutrients.}, keywords = {article, articles, isotopes, Rhubidium, isotopes, Strontium, journal, journals, Larrea, nutrient uptake, nutrient uptake, shrubs, Prosopis, nutrient uptake, Rhubidium, shrub, nutrient uptake, Strontium, tracer, Rhubidium, tracer, Strontium}, author = {Ho, Mengchi and Roisman, R. E. and R. A. Virginia} } @conference {51372, title = {User-friendly soil testing for the tropics}, booktitle = {American Society of Agronomy Meeting}, year = {1996}, month = {November 3-7, 19}, pages = {52}, keywords = {soil testing, tropics}, author = {Snapp, S.S. and Morrone, V.L. and Jeffrey E. Herrick} } @conference {51415, title = {Use of time-series satellite data to identify mesquite response to stress as an indicator of ecosystem health}, booktitle = {Wildland Shrub Symposium}, year = {1995}, month = {May 23-25, 1995}, pages = {22}, abstract = {

Since the late nineteenth century the Jornada Experimental Range has undergone change from grassland to a mixed shrubland ecosystem, and could be considered in less healthy condition as a result. The phenological response of mesquite dominated ecosystems to environmental stressors was analyzed through the use of high temporal resolution satellite data and environmental stressor data. Four mesquite and four grassland sites with variable composition and cover were selected, along with concomitant precipitation, grazing history and herbicide treatment as major stressors. Satellite data for the period 1987 through 1993 from the Advanced Very High Resolution Radiometer (AVHRR) were used to calculate the Normalized Difference Vegetation Index (NDVI), which is a measure of vegetation greenness. Values for NDVI from between 12 and 14 images at approximately 17-day intervals for each year from mid March through early October, were plotted on a site-by-site basis, and smoothed to produce NDVI temporal profile curves., Metrics calculated from these curves include the intergration of the area under the curve, the ratio of spring to summer of NDVI, the duration of maximum photosynthetic activity, and the date of NDVI, value for green-up and brown-off. Species composition and cover data, and soil color and texture were collected on a sample of field sites, and from aerial photography. Values were obtained for summer, winter and year-round stocking rates, for current year annual, spring and summer rainfall, and for herbicide treatment.\  The data were analyzed to investigate differences between sites and years, and associated between stressors and NDVI response. The NDVI temporal profile curves of mesquite shrub sites are clearly distinct from other ecosystems it is possible to test the hypothesis that the temporal and spatial variability of degraded shrublands is lower than that of grasslands or shrub-grass ecosystems.

}, author = {D. A. Mouat and J. Lancaster and Kuehl, R.O. and Walter G. Whitford} } @proceedings {51416, title = {Use of AIRSAR to identify woody shrub invasion and other indicators of desertification in the Jornada LTER}, volume = {3}, year = {1995}, note = {//NMSU, USDA//LTER III//ProCite field[6]: In}, month = {January 23-26, 1}, pages = {31-34}, abstract = { The objective of this study was to determine if the potential sensitivity of active microwave remote sensing to vegetation structure could be used to assess the degree of shrub invasion of grassland. Polarimetric Airborne Synthetic Aperture Radar (AIRSAR) data were acquired for a semiarid site containing varied mixtures of shrubs and herbaceous vegetation and compared with ground observations of vegetation type and other land-surface characteristics. In this preliminary report we examine the response of radar backscatter intensity to shrub density. The response of other multipolarization parameters will be examined in future work.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, proceeding, proceedings, remote sensing, AIRSAR, shrub encroachment}, author = {Musick, H. Brad and Schaber, Gerald G. and Breed, Carol S.} } @conference {51470, title = {The use of natural passive methods of dispersing and establishing native plants on arid rangelands}, booktitle = {Revegetation and Ecology Session, USDI Fish and Wildlife Service}, year = {1993}, month = {1993}, pages = {7-8}, abstract = {Deterioration of arid rangelands around the world is a major concern to the present and future management of these vast land resources. Revegetation efforts are hampered by excessive inputs with low expectations of success. We are implementing natural passive methods such as water, wind, and animals to disperse and establish desirable grass and shrub species on the Jornada Experimental Range in southern New Mexico. In bajada habitats, we have established small seeding blocks and gully seeders along shallow, gentle sloping drainages utilizing portable watering systems. Once desirable grasses and shrubs are established, they will slow water runoff, deposit soil and debris, and produce seed for downstream seeding. In coppice dune habitats, we are establishing fourwing saltbush (Atriplez canescens (Pursh) Nutt.) in seeding blocks for wind and rodent dispersal of seed to determine its competitive ability with mesquite. Additionally, we are determining the potential of using livestock to increase seed of desirable species in specific areas. These low input methods are being incorporated into routine animal and land management practices that are expected to have long-term influences on changing vegetation patterns.}, keywords = {dispersing, establishing, native plants, natural passive methods}, author = {J.R. Barrow} } @conference {51481, title = {Use of domestic animals as biological control agents of desert shrubs: Problems and promise}, booktitle = {4th Symposium on the Chihuahuan Desert Region: US and Mexico}, year = {1993}, month = {1993}, pages = {11}, abstract = {Inseparable anthropogenic and nonanthropogenic factors have altered the dynamics and form of the Chihuahuan Desert. This alteration is characterized by replacement of desert grasslands with shrub species. When this change is viewed as deleterious, few remedial technologies are available either because of economics or potential ecological constraints. In conjunction with skillful management, domestic animals may provide an accessible bioremediation tool that provides additional nutritional and economic benefits. Attempts to use domestic animals to facilitate vegetational change have been successful; however, failures often occur because of animal rejection of target plants. Aspects of animal preference, plant palatability, and plant toxicity are causes of this rejection that may be biochemically mediated. Focusing on carbon-based phytochemicals within tarbush (Flourensia cernua), we have documented substantial temporal and spatial variability in plant phytochemistry while identifying compounds suspected to influence plant palatability. Furthermore, we have observed considerable variation in animal preference for tarbush within and among animal species. Although chemo- and electromagnetic receptors are generally considered to affect animal preference, we provide evidence that preference is also affected by visceral afferents which signify hepatic toxicosis. Examining plant-animal interactions from a biochemical perspective will enhance our understanding of vegetation change and development of potential restorative technologies.}, keywords = {biological control agents, desert shrubs, domestic animals}, author = {E.L. Fredrickson and Richard E. Estell and Kris Havstad} } @proceedings {51514, title = {Use of floodwater to disperse grass and shrub seeds on native arid lands}, year = {1992}, month = {1992}, pages = {167-169}, publisher = {USDA Forest Service, GTR-INT 289}, address = {Sun Valley, ID}, abstract = {Dry stream channels of arid rangelands are typically more fertile and mesic than adjacent slopes. The productivity of these channels is evident by their relatively abundant plant biomass. Substantial down-channel establishment of seeded and native species from root-plowed and seeded strips was observed on the Jornada Experimental Range. There appears to be good potential for using floodwater as a low-input method of seed dispersal for subsequent revegetation of natural waterways.}, url = {/files/bibliography/362.pdf}, author = {J.R. Barrow} } @proceedings {51556, title = {The use of alternative natural methods of reseeding arid native grasslands}, year = {1991}, month = {April 22-26, 199}, pages = {No. 354}, abstract = {Many native arid grasslands of the world have been invaded by noxious desert shrubs which have degraded overall habitat values, especially forage productivity and soil stability. This trend must be altered, but revegetation by mechanical means is expensive and the chance of successful plant establishment is low. Animals and water, which are successfully utilized by native species for distributing seeds and establishing new plants, were used to study their potential in dispersing seeds of some forage species adapted to arid conditions. Blue panicgrass (Panic um antidotale Betz.), alkali sacaton (Sporobolus airoides Torr.), and fourwing saltbush (Atriplex canescens Pursh Nutt.) seed were inserted directly into steer (Bos taurus) rumens by gelatin capsules. About 50\% of the viable seed passed in less than 72 hours. Quail (Colinus virginianus) fed the small seeded grasses passed from 500 to 2000 viable seed per bird within 24 hours. Grasses were transported and established downstream in the more fertile and mesic flood plain areas from artificially seeded plots growing along natural desert arroyos. A seeder was developed that released seeds into these channels during flooding. They were transported downstream and deposited in moist sediment favorable for germination. These methods are inexpensive in terms of cost, labor, and equipment and could be integrated into land and animal management practices that may potentially increase seeding opportunity for desirable forage species.}, keywords = {arid grasslands, natural methods, reseeding}, author = {J.R. Barrow and Kris Havstad and Gibbens, Robert P.} } @article {51645, title = {Utilization of linear, prediction procedures to evaluate animal response to grazing systems}, journal = {Journal of Range Management}, volume = {43}, year = {1990}, note = {//??//NONE//}, month = {1990}, pages = {396-400}, keywords = {animal performance, article, articles, grazing systems, journal, journals}, author = {J. A. Winder and Reldon F. Beck} } @book {51692, title = {The use of variation in the natural abundance of 15N to assess symbiotic nitrogen fixation by woody plants}, series = {Stable Isotopes in Ecological Research}, volume = {Ecological Studies}, year = {1989}, note = {//OTHER//LTER II//Listed in LTER3 proposal as citing LTER2 support//ProCite field[6]: InProCite field[24]: Volume 68}, month = {1989}, pages = {375-395}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York}, abstract = {

This paper will present selected examples of applications of the natural abundance method to ecological studies. The emphasis will be on results from ongoing ecosystem level studies examining the role of woody legumes in N cycling in warm deserts... Data from other systems (tropical forest, chaparral) where significant sustained inputs of N fixed by woody plants may affect ecosystem processes are also discussed to demonstrate the utility of the natural abundance method in a diversity of systems. The natural 15N abundance approach in an important advancement for the study of deeply rooted plants. Our studies have show that contrary to previous speculation, deeply rooted plants in arid ecosystems can support root symbioses at depths not easily studied using other techniques.

}, keywords = {book, books, chapter, chapters, ecosystem, woody plants, nitrogen fixation, nitrogen fixation, symbiotic, nitrogen isotope, nitrogen, 15N, plant, woody, nitrogen fixation, report, reports, tracer, 15N, woody plants}, url = {files/bibliography/JRN00113.pdf}, author = {R. A. Virginia and W. M. Jarrell and P. Rundel and Shearer, G. and Kohl, D. H.}, editor = {P. Rundel and J. R. Ehleringer and K. A. Nagy} } @article {51729, title = {The use of ion-exchange resin bags for measuring nutrient availability in an arid ecosystem}, journal = {Plant and Soil}, volume = {105}, year = {1988}, note = {//NMSU//LTER I//}, month = {1988}, pages = {105-111}, abstract = {

An in situ resin bag technique was used to measure the relative availabilities of N and P along a chronosequence of soils in southern New Mexico, and was compared to two more common indices of nutrient availability. Accumulations of N and P during 10-week intervals over and 18 month period were separable into wet season (September-January) and dry season (February-August) groups, with wet season values significantly greater than dry season values. Only accumulations during the wet season showed significant differences among sites, thus stressing the role of field water regime in interpreting resin accumulation results. Although accumulation patterns of N and P were similar to patterns of \%N and \%P in shrub species growing along the chronosequence, these similarities were not statistically significant. A laboratory experiment demonstrated that bicarbonate-form anion resins are preferable to hydroxyl-form resins, as long as standards are made from solutions extracted by resins to account for variable ion recovery efficiencies.

}, keywords = {article, articles, chronosequence, journal, journals, mineralization, nitrogen, nutrient availability, phosphorus, soil, chronosequence, technique, ion exchange resin bag}, doi = {10.1007/BF02371147 }, url = {files/bibliography/JRN00087.pdf}, author = {Kate Lajtha} } @article {51737, title = {Use of leader lengths and diameters to estimate production and utilization of Cercocarpus breviflorus}, journal = {Journal of Range Management}, volume = {41}, number = {2}, year = {1988}, note = {//LOCAL//NONE//}, month = {1988}, pages = {153-155}, abstract = {Weight relations for twig lengths and diameters were determined for hairy mountain mahogany plants in southern New Mexico. Both twig lengths and twig diameters were related linearly to twig weights. Twig length and twig diameters explained more than 80\% of the variation in twig weight. The equation y(g)= -0.68+0.3 (length) + 6.33 (diameter) resulted in the highest r2 (0.88) value compared to either length or diameter alone. Thus, twig length and diameter measurements could be used to determined production and utilization of hairy mountain mahogany. These relationships probably, however, vary with environmental context.}, keywords = {article, articles, Cercocarpus, productivity, journal, journals, plant, Cercocarpus, plant, hairy mountain mahogany}, author = {Mahgoub, El Fatih and Pieper, Rex D. and Melchor Ortiz} } @article {51807, title = {Using digital pedometers to monitor travel of cows grazing arid rangelands}, journal = {Applied Animal Behavior Science}, volume = {16}, year = {1986}, note = {Reprinted with permission from Elsevier, {\textcopyright} 1986. http://www.sciencedirect.com/science/journal/01681591}, month = {1986}, pages = {11-23}, abstract = {Cows grazing large (3000+ ha) arid rangeland paddocks were fitted with digital pedometers. Raw pedometer readings should be corrected for instrument and cow biases by calibrating the pedometers to individual cows because both cows and pedometers exhibited substantial variability. If routine procedures are followed for recording pedometer readings and adjusting them with the calibration information, digital pedometers appear to be a promising tool to monitor travel of grazing cows. In the context of this study, age of cow and pregnancy status had no apparent effect on the distance these mature cows traveled. However, genotype, external parasites and movement of the herd to a new paddock did have an influence. Because mean daily travel of grazing cows appears to be influenced by management decisions, the impact of various management alternatives de-serves further research. Bipedometered cows can contribute to such research, but this work shows that accurate comparisons of distances traveled require a substantial number of bipedometered cows.}, keywords = {cows, digital pedometers, grazing, monitor, rangelands}, url = {/files/bibliography/285.pdf}, author = {D.M. Anderson and Urquhart, N.S.} } @proceedings {51840, title = {Upper Cenozoic Palomas Formation of south-central New Mexico}, year = {1986}, note = {//OTHER//NONE//}, month = {1986}, pages = {239-247}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, address = {Truth or Consequences, New Mexico}, abstract = {Upper Santa Fe Group deposits occurring in the Palomas, Engel, and San Marcial Basins of the southern Rio Grande rift are here named the Palomas Formation. The term "Palomas gravel" was first applied to Plio-Pleistocene basin fill in the region in 1907; however, the formation has never been formally defined. It consists mainly of alluvial-fan and coalescent-fan deposits (piedmont facies) and ancestral Rio Grande fluvial deposits (axial-river facies). Maximum thickness range from 100 to locally more than 130 m. Formation deposition probably began prior to 5 my and continued until 400,000-500,000 years ago. The formation can be distinguished from the other upper Santa Fe Group deposits by its extensive piedmont facies and relatively narrow belt of axial-river deposits. Older Santa Fe units (Miocene-latest Oligocene), which do not contain axial-river facies, occupy remnants of early rift basins that predate development of the present system of basins and uplifts.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, geology, geomorphology, Palomas Formation, proceeding, proceedings}, author = {Lozinsky, Richard P. and J. Hawley} } @conference {51975, title = {Utilization of tobosa standing crop by cattle under seasonal-rotation and seasonal-continuous grazing on a semidesert rangeland}, booktitle = {36th Annual Meeting, Society for Range Management}, year = {1983}, month = {February 14-18, }, pages = {287}, address = {Albuquerque, NM}, abstract = {A seasonal-rotation, 10-paddock-1 herd cell was compared to seasonal-continuous stocking on a tobosa (Hilaria mutica) range located on the Jornada Experimental Range in southern New Mexico during the 1980 and 1981 summer grazing seasons. Bos taurus and Bos taurus x Bos indicus cattle were used to stock the two treatments. Standing crop was sampled throughout the season in 1980 and 1981 in both treatments using the step-point intercept method to determine the degree of defoliation, except in 1980 when a line-intercept method was used initially to estimate plant cover. The number of tobosa plants grazed per day was significantly (P<0.05) greater in the cell than in the continuously stocked paddock. Likewise, grazing reduced the mean height of the tobosa significantly (PHilaria mutica) range located on the Jornada Experimental Range in southern New Mexico was managed under these methods during the 1980 and 1981 grazing seasons. The SDG paddock had significantly higher tobosa composition compared to the continuous paddock during both years (P<0.05).... Grouping paddocks according to size indicated that small paddocks had significantly more plants which were defoliated compared to the two large SDG paddocks and the continuous paddock during both years (P<0.05).... The degree and amount of change in height imposed on tobosa by grazing animals varied between treatments during both years.... There was no significant difference between treatments with regard to average daily gains of livestock during both years (P<0.05).}, keywords = {cattle grazing,Hilaria utilization, dissertation, dissertations, grassland,cattle utilization, Hilaria,cattle utilization, management,cattle grazing, theses, thesis}, author = {Tadingar, Toloumbaye} } @inbook {52122, title = {Utilization of grass- and shrublands of the southwestern United States}, booktitle = {Management of Semiarid Ecosystems}, year = {1979}, month = {1979}, pages = {161-203}, publisher = {Elsevier Scientific Publishing Co.}, organization = {Elsevier Scientific Publishing Co.}, chapter = {5}, address = {New York, NY}, abstract = {The rangelands of the Southwestern United States may seem limitless, but as a renewable source for livestock grazing, they are fragile, easily damaged by abuse and subject to droughts. The original vegetation on large parts of these lands has been depleted by a combination of these factors and a rapid increase of unwanted shrubs. Table 5.1 shows the area in rangeland and the livestock numbers in Table 5.1 are the totals for each state, the rangeland areas considered in this chapter are roughly the western half of Texas and Oklahoma, most of New Mexico and all but the southwestern quarter of Arizona.}, keywords = {Southwestern rangelands, utilization}, url = {/files/bibliography/171.pdf}, author = {C.H. Herbel}, editor = {Brian Walker} } @article {52150, title = {The use of termites and other soil fauna to develop soils on strip mine spoils}, year = {1978}, note = {//OTHER//NONE//}, month = {1978}, institution = {Rocky Mountain Forest and Range Experiment Station}, edition = {Research Note RM-361}, abstract = {A laboratory study showed that soil arthropods, especially naturally occurring subterranean termites can produce beneficial changes in the physical and chemical characteristics of mine spoil material.}, keywords = {arthropod,also SEE , book, books, chapter, chapters, mine spoils,reclamation, reclamation, reclamation mine spoil, report, reports, soil arthropod,mine spoils, soil fauna,mine spoils}, author = {George Ettershank and Ned Z. Elkins and Perseu F. Santos and Walter G. Whitford and Earl F. Aldon} } @conference {52190, title = {UV-B radiation effects on photosynthesis and plant growth}, booktitle = {Research Symposium, UV-B Radiation: Biological and Climatic Effects Workshop}, year = {1977}, month = {September 19-21,}, address = {University of Maryland}, author = {Sisson, W.B.} } @article {52252, title = {US/IBP Desert Biome Research Memorandum 72-26}, year = {1975}, note = {ProCite field[2]: Studies on wood borers, girdlers and seed predators of mesquite.ProCite field[6]: In}, month = {1975}, pages = {15-21 pp.}, edition = {3}, abstract = {The study was designed to determine the response of honey mesquite (Prosopis glandulosa) to varying levels of insect damage. Because of difficulties encountered in getting the insects to affect the plants in varying degrees, damage of the type done by the mesquite twig girdler (Oncideres sp.) and a node borer (family Bostrichidae) was simulated.....}, keywords = {book, books, chapter, chapters, report, reports}, isbn = {Final Report}, author = {Walter G. Whitford and R. K. Johnson and D. J. DePree} } @proceedings {52272, title = {Utilizing tobosa (Hilaria mutica [Buckl.] Benth.) during the winter and spring}, year = {1974}, month = {1974}, pages = {184-190}, address = {Moscow, USSR}, abstract = {Tobosa (Hilaria mutixa [Buckl. ] Benth.) is a coarse, unpalatable grass when it is dormant. It grows on floodplains, which often have a higher production than adjacent, upland areas. Therefore, it is an important resource, often underutilized, in the arid, semidesert region of the southwestern United States. The objective of this study was todetermine if tobosa could be used by weaned calves during the winter-spring period when it is mostly dormant. Herbel found that nitrogen (N) fertilization increased tobosa production on floodplains 2 years during 1957-61. N fertilization increased crude protein of mature tobosa herbage in four of the five years. During 1966-70, Dwyer found that 67 kg/ha of N increased herbage production 2 years. He recommended burning tobosa to remove old growth in early summer, shortly after initiation of new growth. According to Ares, tobosa hay harvested when the plants were green and succulent was readily consumed by cattle. Paulsen showed that cattle grazed dormant tobosa sprayed with molasses much more readily than untreated tobosa.}, url = {/files/bibliography/152.pdf}, author = {C.H. Herbel and Nelson, A.B.} } @article {52339, title = {Using mechanical equipment to modify the seedling environment}, year = {1972}, month = {1972}, pages = {369-381}, institution = {Wildland Shrubs--Their Ecology and Utilization, U.S. Department of Agriculture, General Technical Report INT-1}, abstract = {In arid and semiarid zones, the soil surface is infrequently moistened and the evaporation rate is high. Establishing seedlings is often difficult because of an adverse microenvironment (rapid drying, unfavorable temperatures and crusting of the soil surface). Accordingly, the primary objective of seeding procedures is to place the seed in a favorable environment for germination and establishment of the seedling. This often requires varying the procedure to fit the site. Good seedbed preparation for range seeding in some areas involves retaining a firm seedbed that favors infiltration and storage of moisture and leaving a trash-covered surface (Pearse, 1952). Shallow disking, or other treatment that reduces weed competition, generally accomplishes these objectives. More intensive tillage is usually avoided not only because of increased cost but also because of the problem of excessive disturbance of the soil surface, bringing up heavier subsoils, or burying the friable topsoil and litter. Wind erosion is often a problem on loose, unprotected seedbeds. Loose seedbeds should be allowed to settle or be otherwise compacted before seeding. In this paper, press wheel is used to describe soil firming prior to seeding, and packer wheel is used to describe soil firming after seeding. A scalper blade is a sweep that removes debris and plant competition from a seeded row. Ripping is used to describe a method of fracturing a hardpan, plowpan, or other impenetrable layer that impedes infiltration of moisture. Pits are shallow indentations or basins made in the surface of the soil to retain water from rainfall or snowmelt on a site.}, keywords = {government publication, mechanical equipment, microenvironment, seedling environment}, url = {/files/bibliography/134.pdf}, author = {C.H. Herbel} } @mastersthesis {52444, title = {Use of indicators in digestibility studies with tobosa (Hilaria mutica)}, year = {1967}, note = {//??//NONE//}, month = {1967}, pages = {42}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, keywords = {cattle,Hilaria, dissertation, dissertations, Hilaria,digestibility, theses, thesis}, author = {H.A. Barry} } @article {52531, title = {The use of meal-salt mix for better distribution of cattle}, journal = {American Cattle Producer}, volume = {35}, number = {4}, year = {1953}, month = {September 1953}, pages = {9-11}, abstract = {A basic principle of good range management is distributing livestock so that utilization of forage will be as uniform as possible on all parts of the range. Cattle naturally tend to congregate near watering plces and on level or other favored areas with the result that, unless provisions are made for distributions, parts of the range are too heavily grazed, parts are grazed to the proper degree, and parts receive little or no grazing use. Many methods are used to encourage more uniform cattle grazing. Fencing into small range units and developing watering facilities are effective but limited by economic considerations. Placing salt in little used areas, periodic closing of watering places, and herding and riding are helpful practices. Yet, because of the natural grazing habits of cattle and the rough character of most rangelands, the pattern of grazing use is seldom fully satisfactory. A possible new tool for controlling cattle distribution is provided by a cottonseed meal-salt mixture which is becoming a widely used supplemental range feed, especially in the Southwest.}, keywords = {cottonseed meal-salt mixture, forage utilization, range management, uniform grazing}, url = {/files/bibliography/078.pdf}, author = {F.N. Ares} } @article {52574, title = {The use of phosphorus and calcium supplements for range livestock in New Mexico}, year = {1942}, note = {//??//NONE//}, month = {1942}, institution = {New Mexico Agricultural Experiment Station}, address = {Las Cruces, New Mexico}, keywords = {book, books, calcium,cattle, cattle,nutrient supplement, chapter, chapters, nutrient,cattle supplement, phosphorous,cattle, report, reports}, isbn = {Bulletin 287}, author = {Knox, J. H. and Watkins, W. E.} } @article {52602, title = {Using salt to regulate grazing}, journal = {American Hereford Journal}, volume = {28}, year = {1937}, month = {1937}, pages = {30-31}, keywords = {grazing, regulate, salt}, author = {Weir, W.W.} } @article {52631, title = {The use of salt in range management}, year = {1926}, month = {July 1926}, pages = {32 }, publisher = {U.S. Department of Agriculture, Department Circular 379, U.S. Government Printing Office}, abstract = {

With an adequate quantity of salt, grazing animals develop better than they would otherwise, are more contented and are more easily handled (fig. 1). Also, proper quantity and distribution of salt on the range go a long way towards controlling livestock grazing and obtaining satisfactory use and maintenance of forage. On western grazing lands, salting is unusually important because the livestock graze under open-range conditions, and the problem of obtaining proper forage use is complicated by considerations of topography, accessibility, watering facilities and other factors affecting distribution of stock. The wide variation in conditions and the lack of well-defined rules have led to greater diversity in the way range salting is done than exists in almost any other practice connected with the range livestock industry. It is the object of this circular to bring together the results of experimental work, careful observations and studies of existing practices and to outline principles of adequate range salting of livestock in the West.

}, keywords = {forage maintenance, government publication, grazing, livestock, range management, salt}, url = {/files/bibliography/011_0.pdf}, author = {Chapline, W.R. and Talbot, M.W.} } @article {52634, title = {The utility of yucca and chamisa as range supplements}, year = {1922}, note = {//??//NONE//}, month = {1922}, institution = {New Mexico Agricultural Experiment Station}, keywords = {Atriplex,range supplement, book, books, cattle,Atriplex, cattle,Yucca, chapter, chapters, report, reports, Yucca,range supplement}, isbn = {Bulletin 133}, author = {Brown, L. S.} }