@proceedings {JRN55369, title = {Opportunities and challenges of grass-finishing on desert pastures}, year = {2022}, month = {3/30/2022}, abstract = {We are applying survey and modeling approaches to understand the potential for grass finishing beef cattle in desert agroecosystems ~under future climate expectations. First, we sought to understand the characteristics of current operations and how climate change may impact grass-finishing in the region. We inventoried and surveyed grass-fed beef operations in nine states in the Southwest and Southern Plains and created a web-based map to evaluate their spatial distribution. Survey results showed that: a) grass-fed producers market their cattle in a diversity of ways, although freezer beef was the most ubiquitous, b) producers perceive a number of benefits and challenges involved in raising grass-fed beef and c) some types of decision support tools are clearly preferred over others. The most commonly indicated need for information was regarding drought adaptation and management. Based upon these survey results and key informant interviews, we have initiated two follow-up surveys to better understand the key practices, economics, and market factors influencing viability of grass finishing in the region from the perspective of both producers and processors. Survey data will help parameterize regional socioecological models that characterize current and future grass-finishing~ potential in western U.S. rangelands, and the role that grass-finishing may have in climate adaptation. A first step in modeling has entailed a preliminary ranch-level economic optimization model that can estimate the profitability of ranching operations under climatic change in New Mexico, with downscaled climate projections used to estimate profitability across cattle genetics and climatic conditions. }, keywords = {desert, grass-finishing, pastures}, author = {Skye Aney and Zachary Hurst and Torell, Gregory L} } @proceedings {JRN55361, title = {Oryx (Oryx gazella gazella) presence patterns in a long term grazing study in the Chihuahuan Desert of New Mexico}, year = {2022}, month = {2/8/2022}, abstract = {A long term grazing study comparing the impact of grazing heritage (Raramuri Criollo) vs. commercial (Brangus) beef cattle on desert rangelands was initiated in 2020 at the NMSU Chihuahuan Desert Rangeland Research Center (CDRRC). South African oryx (Oryx gazella gazella) were introduced in the 1970s onto White Sands Missile Range, located ca. 20 miles east of the CDRRC, and oryx are frequently observed in our 5,000 ha study pastures. However, patterns of oryx presence in the grazing experiment pastures have not been determined. Hence, we sought to quantify oryx presence in our study pastures to help clarify: a) their potential impact on our experiment treatments; and b) cattle-, vegetation-, season- and ranch infrastructure- related factors associated with patterns of oryx presence in our experimental pastures. We obtained ca. 2,250 images from 40 trail cameras located in our four study pastures (10 cameras/pasture). Images were collected over a nine month phase repeated in two consecutive years, 2020 and 2021. Annually, images were collected during 3 periods: a) pre-grazing (Dec{\textendash}Feb), three months prior to placing cattle in the experiment area; b) grazing, when cattle grazed the experiment pastures (Mar{\textendash}May); and c) post-grazing, the three months after cattle were removed from pastures (Jun{\textendash}Aug). Grazing occurred in pastures only in 2020; no grazing occurred in 2021 because of severe drought conditions. These data will be compared with fecal pellet counts observed on permanent 100m transects at the camera locations to corroborate relative oryx presence. Additionally, vegetation cover data were collected at the permanent transects to determine potential relationships between oryx presence and plant cover. Our poster will report on oryx presence patterns across our study pastures with respect to cattle presence, vegetation, ranch infrastructure (distance to roads and drinkers), and season of the year. }, keywords = {Chihuahuan Desert, grazing study, long term, New Mexico, Oryx, Oryx gazella gazella, patterns, presence}, author = {M. Funk and Matthew M. McIntosh and Bender, L. and Andr{\'e}s F. Cibils and Andrew Cox and Fuentes-Soriano, S. and S. Spiegal and Richard E. Estell} } @article {JRN55370, title = {Opportunities to implement manureshed management in the Iowa, North Carolina, and Pennsylvania swine industry}, journal = {Journal of Environmental Quality}, year = {2022}, month = {3/2/2022}, abstract = {The U.S. swine industry is diverse, but opportunities exist to strategically improve manure management, especially given much of the industry{\textquoteright}s vertical integration. We investigate opportunities for improving manureshed management, using swine production examples in Iowa, North Carolina, and Pennsylvania as a lens into historical trends and the current range of management conditions. Manure management reflects regional differences and the specialized nature of hog farms, resulting in a large range of land bases required to assimilate manure generated by these operations. Selected representative farm scenarios were evaluated on an annual basis; farm-level manuresheds were largest for Pennsylvania sow farms and smallest for North Carolina nursery farms. Compared with nitrogen-based manuresheds, phosphorus-based manuresheds were up to 12.5 times larger. Technology advancements are needed to promote export of concentrated nutrients, especially phosphorus, from existing {\textquotedblleft}source{\textquotedblright} manuresheds to suitable croplands. The industry is dynamic, as revealed by historical analysis of the siting of hog barns in Pennsylvania, which are currently trending toward the north and west where there is greater isolation to prevent the spread of disease and a larger land base to assimilate manure. Industry expansion should focus on locating animals in nutrient {\textquotedblleft}sink{\textquotedblright} areas.}, keywords = {Iowa, manureshed management, North Carolina, Pennsylvania, swine industry}, doi = {10.1002/jeq2.20340}, url = {files/bibliography/22-004.pdf}, author = {Robert J Meinen and S. Spiegal and Peter J. A. Kleinman and Colton K Flynn and Sarah Goslee and Robert E Mikesell and C. Church and Ray Bryant and Mark Boggess} } @conference {JRN55314, title = {Opportunities to implement manureshed management in the U.S. poultry industry}, booktitle = {American Society of Ag}, year = {2020}, month = {11/08/2020}, abstract = {US poultry production and processing industries provide close to 2 million jobs and have annual economic impact of close to $500 billion. In 2019, over 9 billion broiler chickens were produced across the US with 60\% or so concentrated in southeastern states. The production of approximately 1.2 kg of manure per broiler chicken poses daunting challenges in terms of beneficial use that is economically and environmentally acceptable. The issue is exacerbated due to production and processing being located in relatively small confined spaces. Currently, opportunities for transporting surplus manure from confined animal operations for use on nutrient-deficient crop and hay lands elsewhere are limited. A potential solution recently proposed by the USDA{\textquoteright}s LTAR Network study is the concept of {\textquotedblleft}Manureshed{\textquotedblright} {\textendash} the lands surrounding confined animal operations onto which manure nutrients can be redistributed to meet production, economic, and environmental goals. Using this concept, this presentation reviews the manure management issues within the poultry production and processing industry and seeks to explore opportunities for intra-county pathways for redistribution of poultry manure nutrients to recouple crop-livestock agricultural systems disconnected for some time due to specialized livestock production industries. Key case studies where local accumulation of poultry manure nutrients are manifest at forefront at a national scale will be examined.}, keywords = {manureshed management, nutrient-deficient crop, poultry manure nutrients, U.S. poultry industry, {\textquotedblleft}Manureshed{\textquotedblright}}, author = {Ray Bryant and Dinku Endale and S. Spiegal and Peter J. A. Kleinman and Colton K Flynn and Meinen, Robert J and Michael Cavigelli and Sabo, Robert} } @conference {JRN55300, title = {Opportunities to implement manureshed management in the U.S. swine industry}, booktitle = {ASA-CSSA-SSSA Annual Meeting Abstracts}, year = {2020}, month = {11/09/2020}, abstract = {Hog production is highly organized, lending itself to strategic management such as that proposed by the manureshed concept of linking animal and crop production systems. This presentation reviews the manure management issues within the hog industry, focusing on key case studies where local accumulation of manure nutrients are manifest at a national scale. Historical trends in the industry point to the role of nutrient budget concerns in its evolution. Despite the challenges of relocating hog manure to areas of high nutrient demand, opportunities exist to adjust its management on farm as well as to integrate manureshed concerns into the long-term expansion of the hog industry.}, author = {Meinen, Robert and S. Spiegal and Peter J. A. Kleinman and Colton K Flynn and Sarah Goslee and Mikesell, Robert and Ray Bryant} } @conference {JRN55065, title = {Observed changes in Upper Rio Grande snowpack water storage and snowmelt timing: 1980 to 2018}, booktitle = {Universities Council on Water Resources}, year = {2019}, month = {06/2019}, address = {Snowbird, UT}, abstract = {

One of the most widely anticipated impacts of climate change on the hydrological cycle of western watersheds is earlier snow melt. Observational studies and hydrological modeling efforts predict diminished snowpack and earlier peak streamflow in watersheds across the western United States. Here we use snow course data of the snowpack telemetry (SNOTEL) network from 16 stations in the Upper Rio Grande watershed with the longest data record (~40-years). Trend analyses with various methodologies (parametric, mann-kendall and regional kendall) and time-windows (1980 to 2018 and 1984 to 2018) augment previous modeling studies. We anticipate that since the observable impacts of climate change are occurring in many sectors, observed data may show a decreasing trend in maximum water equivaled of the snowpack (SWE), earlier snowmelt, shifts in the snowmelt window and a more rapid snowmelt (fewer days between peak snowpack and no snowpack). \ Trend analyses between 1980 and 2018 show the maximum annual water content in snowpack is decreasing, the snowpack is melting earlier and the date of the maximum SWE is earlier in the year. However, the number of days between the peak snowpack and no snowpack did not change {\textendash} indicating that the snowpack was not melting faster. The early 1980{\textquoteright}s was an anomalous wet time, so we tested trends from 1984 to 2018 and found trends similar to those reported using linear regression. \ Maximum SWE declined in 11 of 16 watersheds, maximum SWE was reached earlier in 10 of 16 watersheds and the snowmelt window was earlier in 10 of 16 watersheds. Trends for the 1980 to 2018 and the 1984 to 2018 timeframes were similar, despite controlling for an anomalously wet early 1980{\textquoteright}s. The regional kendall test reflects these trends with significantly decreasing maximum annual SWE, earlier arrival of maximum SWE and an earlier snowmelt window. Over the 40 years of measured snowpack data results indicate that snowmelt is 16 days to 5 weeks earlier, similar to modeling studies comparing a 40 to 70-year timeframe (1999 to midcentury).

}, author = {Emile H. Elias and D. K. James and Sierra Heimel} } @article {JRN54592, title = {On the observed hysteresis in field-scale soil moisture variability and its physical controls}, journal = {Environmental Research Letters}, volume = {11}, year = {2016}, pages = {084008}, abstract = {

The spatiotemporal variability of soil moisture (θ) has rarely been studied at the field scale across different seasons and sites. Here, we utilized 9 months of θ data in two semiarid ecosystems of North America to investigate the key relationship between the spatial mean (〈θ〉) and standard deviation (σ θ ) at the field-scale (~100 m). Analyses revealed a strong seasonal control on the σ θ versus 〈θ〉 relation and the existence of hysteretic cycles where wetting and dry-down phases have notably different behavior. Empirical orthogonal functions (EOFs) showed that θ variability depends on two dominant spatial patterns, with time-stable and seasonally varying contributions in time, respectively. Correlations between EOFs and land surface properties also indicated that θ patterns are linked to vegetation (terrain and soil) factors at the site with higher (lower) vegetation cover. These physical controls explained the observed hysteresis cycles, thus confirming interpretations from previous modeling studies for the first time.

}, keywords = {land surface hydrology, North American monsoon, semi-arid ecosystems, soil moisture field experiment, spatial variability}, doi = {10.1088/1748-9326/11/8/084008}, url = {files/bibliography/JRN00652.pdf}, author = {Mascaro, G. and Enrique Vivoni} } @conference {JRN54429, title = {Operationalizing resilience using state and transition models}, booktitle = {68th World Congress on Ecological Restoration}, year = {2015}, month = {08/2015}, address = {Manchester, UK}, abstract = {

In management, restoration, and policy contexts, the notion of resilience can be confusing. Systematic development of conceptual models of ecological state change (state transition models; STMs) can help overcome semantic confusion and promote a mechanistic understanding of resilience. Drawing on examples from rangelands, I describe basic state change concepts (equilibrium, nonequilibrium, and regime shifts) and how they are matched (or mismatched) to specific ecosystems via historical, comparative, experimental, and monitoring evidence. A key issue is to distinguish regime shifts from other forms of state change. STMs should distinguish strategies used to prevent regime shifts vs. the restoration and management of historical/hybrid/novel ecosystems following a regime shift. Important challenges in the development of STMs include 1) defining reference conditions, 2) considering climate change, and 3) information delivery to users.\  Paper No. SY48.2.

}, author = {Brandon T Bestelmeyer} } @conference {49956, title = {Orthorectification, mosaicking, and analysis of sub-decimeter resolution UAV imagery for rangeland monitoring}, booktitle = {64th Annual Society for Range Management Meeting}, year = {2011}, month = {02/09/2011}, address = {Billings, Montana}, abstract = {Unmanned aerial vehicles (UAVs) offer an attractive platform for acquiring imagery for rangeland monitoring. UAVs can be deployed quickly and repeatedly, and they can obtain sub-decimeter resolution imagery at lower image acquisition costs than with piloted aircraft. Low flying heights result in imagery highly suitable for mapping soil and vegetation types, structure, and pattern in great detail. Small UAVS are commonly equipped with lightweight digital cameras due to low payload capabilities, resulting in challenges associated with photogrammetric processing and creation of orthomosaics from large number of small footprint images. We developed a custom, semi-automated approach that is suitable for processing hundreds of UAV images into orthorectified image mosaics. A customized algorithm improves the accuracy of the UAV{\textquoteright}s exterior orientation data, comprised of position (X, Y, Z) and attitude (roll, pitch, heading) information derived from the UAV{\textquoteright}s flight computer. The corrected exterior orientation data are subsequently used as inputs for orthorectification and mosaicking with minimal or no need for tie- and/or ground control points, greatly reducing time and cost of processing. The workflow has been tested on 65 image mosaics of arid rangelands with few distinguishing features. Orthomosaics created using this process have positional accuracies of 1 m in flat terrain and 1.9 m in hilly terrain. Object-based image analysis of the image mosaics has resulted in classification accuracies of 78\%{\textendash}92\%, depending on vegetation type and number of classes. The results show that UAVs are viable remote sensing platforms and that quality products can be derived from the imagery. }, author = {Andrea S. Laliberte and Craig Winters and A. Rango} } @conference {50042, title = {Object-based classification of hyperspatial digital mapping camera (DMC) imagery for potential integration into the National Resource Inventory (NRI) of grazing lands}, booktitle = {American Society for Photogrammetry and Remote Sensing (ASPRS) Annual Meeting}, year = {2010}, month = {April 26-30,2010}, address = {San Diego, CA}, abstract = {Land management agencies such as the Bureau of Land Management (BLM) and the Natural Resources Conservation Service (NRCS) are required to monitor and assess vegetation conditions across millions of acres of rangelands and grazing lands. Field-based assessments are very costly and inefficient over large areas; remote sensing offers the potential to increase the number of monitoring locations, automate the image classification process, and reduce monitoring costs. Hyperspatial digital aerial photography has great potential to complement or replace ground measurements of vegetation cover. We investigated object-based image analysis (OBIA) techniques for classifying vegetation in southwestern U.S. arid rangelands with 4 cm resolution digital aerial photography. We obtained high r-square values for image- and ground-based measures of percent cover (r-square values: 0.82-0.92). OBIA enabled us to automate the classification process by applying a process tree developed on one image iteratively to subsequent images of the same vegetation community. The ability to classify multiple images efficiently offers the potential to increase the precision of national level inventories by increasing sample locations and to reduce costs by requiring fewer personnel to obtain ground measurements. This approach has demonstrated potential for quantifying fine-scale land cover attributes with very high resolution digital imagery, and exhibits promise for nationwide application for monitoring grazing lands.}, keywords = {aerial photography, digital mapping camera, grazing lands, National Resource Inventory, object-based classification}, author = {Andrea S. Laliberte and Dawn M. Browning and Jeffrey E. Herrick and Peg Gronemeyer} } @article {50063, title = {One-Seed Juniper Sapling Use by Goats in Relation to Stocking Density and Mixed Grazing With Sheep}, journal = {Rangeland Ecology \& Management}, volume = {63}, number = {3}, year = {2010}, note = {doi: 10.2111/08-215.1}, pages = {373-386}, publisher = {Society for Range Management}, abstract = {To successfully suppress reinvasion of one-seed juniper (Juniper monosperma [Englem.] Sarg.) with goats, defoliation of newly established saplings must be enhanced to levels that eventually kill or suppress plant growth. We tested the effect of stocking density and mixed grazing with sheep as potential grazing strategies to increase utilization of one-seed juniper saplings by goats. In summer and spring, groups of 10 does (Goats alone, GA) or 5 does and 4 ewes (Mixed grazing, MG), grazed 20 x 30 m cells infested with saplings (500-533/ha; 0.8 m tall), either continuously for 6 days (Low stocking density, LD) or with daily rotation through 10x10m cells during the 6 day period (High stocking density, HD) in a block design. Frequency of saplings with light, moderate and heavy bark and foliage use, feeding activity, juniper in feces, and utilization of herbaceous vegetation were determined. Goats in HD treatment spent more time feeding on saplings, less time feeding on herbaceous forages, and tended to achieve diets with more juniper than goats in LD. Utilization of herbaceous vegetation ranged from 52 to 73\% and was higher for MG than GA and for LD than HD. The MG-HD treatment resulted in highest frequency of short saplings (< 0.5m) with high percent (> 66\%) of defoliated branches in summer and spring, and lowest frequency of saplings with low percent (< 33\%) of debarked branches in spring. Heavy defoliation was more frequent in shorter saplings, whereas heavy debarking occurred mostly in tall saplings. The results of this study suggest that stocking density and mixed grazing stimulate feeding behaviors that increase utilization of juniper saplings by goats.}, keywords = {diet mixing, grazing systems, targeted grazing, uniper control}, isbn = {1550-7424}, doi = {10.2111/08-215.1}, url = {http://handle.nal.usda.gov/10113/58280}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and Terrell T. Baker and J.W. Walker} } @conference {50293, title = {One-seed juniper use by goats: Influence of stocking density and mixed grazing in summer and spring}, booktitle = {Society for Range Management Annual Meeting}, series = {Society for Range Management Annual Meeting}, year = {2008}, month = {January 26-31, 2}, pages = {1952}, address = {Louisville, KY}, abstract = {

Targeted grazing with goats could be used to suppress one-seed juniper (Juniperus monosperma) sapling invasion if suitable grazing techniques are identified and applied. We examined the effects of stocking density and mixed grazing with sheep on utilization of herbaceous vegetation and juniper saplings (\< 2m) by Boer-Spanish goats in summer and spring. The study was a 2x2 factorial with two herbivores and two stocking densities. Ten goats (Goats alone) or five nannies mixed with four Rambouillet ewes (Mixed grazing) were placed in 10x10 m plots for one day (High Density) or 20x30 m plots for six days (Low Density). Stocking rate for both treatments was 1.1 AU/ha/yr. There were two complete blocks in each season. Time spent feeding on juniper (TFJ; \%) and utilization of herbaceous vegetation (UHV; \%) were determined. There were no differences in TFJ (P=0.99) nor UHV (P=0.27) between seasons. TFJ varied by herbivore and density treatment (herbivore x density: P = 0.16). Goats spent more time feeding on juniper in high vs. low stocking density treatments (P=0.01), although differences in TFJ among stocking density treatments were larger in mixed grazing plots (34.4 vs. 17.7\% \± 3.5) than in plots where goats grazed alone (28.2 vs. 22.2\% \± 3.6). UHV was higher in low vs. high stocking density plots (67.0 vs. 59.6\% \± 2.3; P=0.05) and in plots with mixed grazing vs. goats grazing alone (69.8 vs. 56.9\% \± 2.4; P\<0.01). High density grazing and mixed grazing with goats and sheep can increase the use of juniper by goats. Low density grazing appears to encourage selective grazing which results in more intensive use of herbaceous understory. Overall, stocking density and mixed grazing are two promising techniques to manipulate juniper and herbaceous plant utilization in targeted grazing programs with goats.

}, keywords = {abstract, abstracts, density, juniper, one-seed}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and J.W. Walker} } @article {50352, title = {An object-based image analysis approach for determining fractional cover of senescent and green vegetation with digital plot photography}, journal = {Journal of Arid Environments}, volume = {69}, year = {2007}, month = {2007}, pages = {1-14}, abstract = {

Research into automatic image processing of digital plot photography has increased in recent years. However, in most studies only overall vegetation cover is estimated. In arid regions of the southwestern US, grass cover is typically a mixture of green and senescent plant material and it is important to be able to quantify both types of vegetation. Our objectives were to develop an image analysis approach for estimating fractional cover of green and senescent vegetation using very high-resolution ground photography, and to compare image- and ground-based estimates. We acquired ground photography for fifty plots using an eight megapixel digital camera. The images were transformed from the RGB (red, green, blue) color space to the IHS (intensity, hue, saturation) color space. We used an object-based image analysis approach to classify the images into soil, shadow, green vegetation, and senescent vegetation. Shadow and soil were effectively masked out by using the intensity and saturation bands, and a nearest neighbor classification was used to separate green and senescent vegetation using intensity, hue and saturation as well as visible bands. Correlation coefficients between ground- and image-based estimates for green and senescent vegetation were 0.88 and 0.95 respectively. Image analysis underestimated total and senescent vegetation by approximately 5\%. The object-based image-processing approach is less labor and time intensive than the ground-based plot method, is a viable alternative to these methods, and has the potential to be incorporated into rangeland monitoring protocols.

}, keywords = {object-based image analysis, rangeland monitoring, rangeland vegetation, very high-resolution images}, doi = {10.1016/j.jaridenv.2006.08.016}, url = {/files/bibliography/07-001.pdf}, author = {Andrea S. Laliberte and A. Rango and Jeffrey E. Herrick and E.L. Fredrickson and Laura M. Burkett} } @conference {50395, title = {One seed juniper intake by sheep and goats supplemented with degradable or by-pass protein}, booktitle = {Society for Range Management Meeting Proceedings}, year = {2007}, month = {February 9-16, 2}, pages = {Paper No. 448}, address = {Reno/Sparks, NV}, abstract = {Successful prescribed grazing of one seed juniper (Juniperus monosperma Englem. Sarg.) with sheep and goats may depend on identifying times of the year when juniper terpenoid levels are less likely to deter herbivory and could be contingent on the use of protein supplements to help animals detoxify terpenes and boost intake. We conducted pen trials with sheep and goats to determine if individual juniper intake varied seasonally (summer, fall, winter, or spring) or was affected by the amount and kind of crude protein (CP) in the diet. Twelve Ramboullet ewes and 12 Spanish-boer goats were offered a basal diet of sudangrass or bermudagrass hay with either no protein added (Control diet: 5\% CP), or with soybean meal (degradable CP: DCP) or fishmeal (by-pass CP:BPCP) to achieve two treatment diets with 12.5\% CP each. Diets were offered at 1.6\% of body weight (BW) to each animal for 10 days of adaptation and 10 days of data collection in each season. Juniper trials were a 30 min feeding bout on juniper branches (175g) attached to wooden stands (0.8 m height). Juniper intake per unit of BW (J1) varied amoung herbivore species. J1 varied among diets (P=0.02) was highest for animals receiving the DCP and BPCP supplements and lowest for control animals. J1 also varied among seasons, intermediate in spring and summer, and lowest during the fall. Sheep and, especially, goats could be used in prescribed grazing programs to suppress juniper re-invasion. Great suppression could be expected from goats browsing during winter, provided that protein levels are sufficient to allow animals to detoxify terpenoids.}, keywords = {by-pass protein, goats, juniper, sheep}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and S. Soto-Navarro} } @article {50462, title = {One- and two-dimensional modelling of overland flow in semiarid shrubland, Jornada basin, New Mexico}, journal = {Hydrological Processes}, volume = {20}, year = {2006}, note = {//NMSU//LTER IV//Entered 06/09/2006}, month = {2006}, pages = {1027-1046}, abstract = {

Two distributed parameter models, a one-dimensional (1D) model and a two-dimensional (2D) model, are developed to simulate overland flow in two small semiarid shrubland watersheds in the Jornada basin, southern New Mexico. The models are event-based and represent each watershed by an array of 1-m2 cells, in which the cell size is approximately equal to the average area of the shrubs. Each model uses only six parameters, for which values are obtained from field surveys and rainfall simulation experiments. In the 1D model, flow volumes through a fixed network are computed by a simple finite-difference solution to the 1D kinematic wave equation. In the 2D model, flow directions and volumes are computed by a second-order predictor{\textendash}corrector finite-difference solution to the 2D kinematic wave equation, in which flow routing is implicit and may vary in response to flow conditions. The models are compared in terms of the runoff hydrograph and the spatial distribution of runoff. The simulation results suggest that both the 1D and the 2D models have much to offer as tools for the large-scale study of overland flow. Because it is based on a fixed flow network, the 1D model is better suited to the study of runoff due to individual rainfall events, whereas the 2D model may, with further development, be used to study both runoff and erosion during multiple rainfall events in which the dynamic nature of the terrain becomes an important consideration. Copyright {\~a} 2006 John Wiley \& Sons, Ltd.

}, keywords = {article, drainage basin, hydrology, infiltration, journal, overland flow, runoff}, doi = {10.1002/hyp.5922}, url = {files/bibliography/JRN00452.pdf}, author = {David A. Howes and Athol D. Abrahams and Pitman, E. Bruce} } @conference {50512, title = {One Seed Juniper Intake by Sheep and Goats Supplemented with Degradable or By-Pass Protein}, booktitle = {14th Wildland Shrub Symposium}, year = {2006}, month = {June 6-8, 2006}, abstract = {Suppression of one-seed juniper (Juniperus monosperma Englem. Sarg.) re-invasion into previously cleared woodlands is an increasingly challenging endeavor for New Mexico ranchers. Prescribed burn regulations are becoming more stringent, herbicide application is often costly, and demands by the general public to conduct management perceived as being environment-friendly are increasing rapidly. Prescribed grazing with sheep and goats is an alternative suppression method that could be used within the land management constraints described above. A successful prescribed grazing plan, however, may depend on identifying times of the year when juniper terpenoid levels are less likely to deter herbivory and may be contingent on the use of supplements to help animals detoxify terpenes and boost intake. We conducted a pen experiment with sheep and goats to determine if individual juniper intake varied seasonally (summer, fall or winter) or was affected by the amount and kind of crude protein (CP) in the diet. Twelve Ramboullet ewes and 12 Spanish-Boer goats were offered a basal diet of sudangrass hay with either no protein added (Control diet: 5\% CP), or with soybean meal (degradable CP: DCP) or fishmeal (by-pass CP: BPCP) to achieve two treatment diets with 12.5 \% CP each. Diets were offered at 1.6\% of body weight (BW) to each animal for 10 days during each season. Overnight fasting (10 h) was applied prior to juniper browsing trials that were conducted during the morning hours. Juniper trials consisted of a 30 min feeding bout on juniper branches (175g) attached to wooden stands (0.8 m height). Juniper intake ({\textpm} 1 g) was calculated as the difference between pre- and post- trial juniper biomass corrected by the water loss of 5 control juniper stands. Juniper intake per unit of BW (JI) varied among herbivore species and was greater for goats than sheep (Goats: 0.54g kgBW-1 vs. Sheep: 0.23g kgBW-1). JI varied among diets and was highest for animals receiving the DCP (0.5g kgBW-1) and BPCP (0.41g kgBW-1) supplements and lowest for control animals (0.25g kgBW-1). JI also varied among seasons and was highest in winter (0.54g kgBW-1), intermediate in summer (0.38g kgBW-1) and lowest during the fall (0.23g kgBW-1). Sheep and, especially, goats could be used in prescribed grazing programs to suppress juniper re-invasion. Greater suppression could be expected from goats browsing during winter, provided that protein levels are sufficient to allow animals to detoxify terpenoids.}, keywords = {ewes, goats, juniper, prescribed burn}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and S. Soto-Navarro and Ross, T.T. and S. Ivey and M.K. Petersen and Biacomini, M. and S.H. Cox and M. Rubio} } @conference {50514, title = {One Seed Juniper Intake by Sheep and Goats Supplemented with Degradable or By-Pass Protein}, booktitle = {New Mexico Section Range Science Winter Meetings}, year = {2006}, month = {January 12-13, 2}, address = {Las Cruces, NM}, abstract = {Re-invasion of one seed juniper previously cleared woodlands is a concern of range managers throughout the southwestern United States. Prescribed browsing with sheep and goats could be used as a juniper control method. Success with this tool may depend on improving the herbivore{\textquoteright}s ability to detoxify plant terpenoids in order to induce levels of herbivory that are likely to suppress juniper growth and recruitment. Our objective was to test the effect of two kinds of protein supplementation on juniper consumption by sheep and goats. One seed juniper intake was compared in sheep and goats fed diets varying in amount and quality of crude protein during three seasons (summer, fall, and winter). Goats consumed significantly more juniper than ewes and protein supplements more than doubled juniper intake by both sheep and goats. Goats aggressively defoliated juniper branches, while sheep consumed leaves in a more selective manner. In summary, sheep and goats have potential for use to suppress juniper sapling encroachment. Goats consumed more juniper and protein supplements had a stronger influence on juniper intake of goats.}, keywords = {goats, juniper, protein, sheep}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and S. Soto-Navarro and Ross, T.T. and S. Ivey and Giacomini, M. and M.K. Petersen and S.H. Cox and M. Rubio} } @proceedings {50520, title = {Observations of snow and ice crystals with low temperature scanning electron microscopy (Review)}, year = {2006}, month = {04/2006}, pages = {3-14}, address = {Las Cruces, NM}, abstract = {This review summarizes the advantages of LTSEM for observations of samples of snow and ice by illustrating the type of surface information that is obtainable, the resolution that can be attained and how the depth of field allows one to observe crystals with significant topography. In addition, we illustrate samples collected from remote locations, samples from time sequences during a storm and finally show examples of snow and ice biota as well as, artificial and Martian snow.}, keywords = {ice crystals, low temperature, scanning electron microscopy, snow crystals}, url = {/files/bibliography/06-077.pdf}, author = {W.P. Wergin and A. Rango and J. Foster and E. G. Josberger and E. R. Erbe and C.D. Pooley} } @article {50683, title = {Object-oriented image analysis for mapping shrub encroachment from 1937-2003 in southern New Mexico}, journal = {Remote Sensing of Environment}, volume = {93}, year = {2004}, month = {September 20, 20}, pages = {198-210}, abstract = {

Shrub encroachment into arid and semiarid grasslands in the southwestern United States is of concern because increased shrub cover leads to declines in species diversity, water availability, grazing capacity, and soil organic matter. Although it is well known that shrubs have increased over time, we have little quantitative information related to the nonlinear nature of this vegetation change over a particular time period. On the USDA-ARS Jornada Experimental Range and the adjacent Chihuahuan Desert Rangeland Research Center (CDRRC)(New Mexico State University) in southern New Mexico, shrub increase has been measured with various ground survey techniques extending back to 1858. For this study, we used 11 aerial photos taken between 1937 and 1996 that covered a 150-ha study area and had sufficient resolution for shrub detection. A QuickBird satellite image provided coverage for 2003. We used image segmentation and object-based classification to monitor vegetation changes over time. Shrub cover increased from 0.9\% in 1937 to 13.1\% in 2003, while grass cover declined from 18.5\% to 1.9\%. Vegetation dynamics reflected changes in precipitation patterns, in particular effects of the 1951-1956 drought. Accuracy assessment showed that shrub and grass cover was underestimated due to the constraint of the pixel size. Eighty-seven percent of all shrubs \>2m2 were detected. The use of object-based classification has advantages over pixel-based classification for the extraction of shrubs from panchromatic aerial and high-resolution satellite imagery. Incorporating both spectral and spatial image information approximates the way humans interpret information visually from aerial photos but has the benefit of an automated classification routine. Combining several scales of analysis in a hierarchical segmentation method is appropriate in an ecological sense and allowed for determining shrub density in coarser level classes. Despite encountering difficulties in analyzing a greatly varying aerial photo dataset, including variability in spectral and spatial resolutions, moisture conditions, time of year of observation, and appearance of grass cover, aerial photos provide an invaluable historic record for monitoring shrub encroachment into a desert grassland.

}, keywords = {aerial photography, desert grassland, mapping, object-based classification, satellite image, segmentation, shrub encroachment}, doi = {10.1016/j.rse.2004.07.011}, url = {/files/bibliography/04-053.pdf}, author = {Andrea S. Laliberte and A. Rango and Kris Havstad and Paris, J.F. and Reldon F. Beck and R.P. McNeely and Amy L. Gonzalez} } @article {50870, title = {Operational snowmelt runoff forecasting in the Spanish Pyrenees using the SRM model}, journal = {Hydrological Processes}, volume = {16}, year = {2002}, month = {2002}, pages = {1583-1591}, abstract = {The snowmelt runoff model (SRM) is used to simulate and forecast the daily discharge of several basins of the Spanish Pyrenees. We describe a method for snow mapping using NOAA{\textendash}AVHRR data and a procedure to estimate retrospectively the accumulated snow water equivalent volume with the SRM. A linear combination of NOAA channels 1 and 2 is used to obtain a snow cover image in which the product is the percentage of the snow-covered area in each pixel. Real-time snowmelt forecasts are generated with the SRM using area snow cover as an input variable. Even in basins with a total absence of historical discharge and meteorological data, the SRM provides an estimation of the daily snowmelt discharge. By integrating the forecasted streamflow over the recession streamflow, snowmelt volume is obtained as a function of time. This function converges asymptotically to the net stored volume of water equivalent of the snowpack. Plotting this integral as a function of time, it is possible to estimate for each basin both the melted snow water equivalent (SWE) and the SWE remaining in storage at any point in the snowmelt season Spanish hydropower companies are using results from the SRM to improve water resource management.}, keywords = {hydrological forecasting, NOAA{\textendash}AVHRR, runoff, snowmelt, SWE}, url = {/files/bibliography/02-002.pdf}, author = {E. Gomez-Landesa and A. Rango} } @proceedings {51041, title = {Observing the Spectral Emissivity of Arid Lands Using Multispectral Thermal Infared Data}, year = {2001}, note = {//?//LTER IV//ProCite field[6]: In}, month = {2001}, address = {Aussois, France}, keywords = {abstract, abstracts, arid lands, conference, conference proceedings, conferences, emissivity, infared, proceeding, proceedings}, author = {T. J. Schmugge and A.N. French and Jerry Ritchie and A. Rango} } @proceedings {51074, title = {Organization of grasslands along ecological gradients: US-Hungarian LTER grassland cooperation}, year = {2000}, month = {January 2000}, pages = {67-76}, address = {Budapest, Hungary}, abstract = {

As a result of discussions based upon common interests, yet with different expertise and approaches, an interdisciplinary team involving two U.S. and eight Hungarian ecologists was formed to implement a collaborative grassland research project funded by the U.S. National Science Foundation, the Hungarian Academy of Sciences, and the Hungarian Science Foundation (OTKA). Our goal was to develop generalizations concerning controls on grassland composition, structure, and dynamics by comparing similar and different types of grasslands across multiple spatial scales on two continents. The specific objectives were to evaluate the importance of current environmental controls on patterns in biodiversity and dynamics in semiarid grasslands, and to evaluate the short- and long-term responses of these grasslands to changes in environmental constraints. Three sites were selected along climatic gradients in each country. Long-term datasets were supplemented with additional sampling for species diversity. An individual plant-based model (ECOTONE) was used to simulate long-term responses to climate and directional changes in climate. Our results showed that the biodiversity and fine scale vegetation patterns show similar trends with increasing aridity in both countries. The ability of ECOTONE to simulate grasslands in Hungary indicates the importance of gap dynamics and related processes in European grasslands as well as in North America. Using the same sampling methods and simulation analyses, we improved our ability to understand controls on grassland structure and biodiversity across climatic gradients. Because our data extend to countries on two continents, our results may have applicability to other semiarid grasslands in the world.

}, keywords = {biodiversity, controls, ECOTONE, gap dynamics, grassland research}, url = {/files/bibliography/572.pdf}, author = {J. R. Gosz and Debra C. Peters and Bartha, S. and Kertesz, M. and Kovacs-Lang, E. and G. Kroel-Dulay} } @article {JRN54976, title = {Operational applications of remote sensing in hydrology: success, prospects and problems }, journal = {Hydrological Sciences}, volume = {43}, year = {1998}, month = {12/1998}, pages = {947-968}, chapter = {947}, abstract = {

The use of remote sensing information in operational hydrology is relatively limited, but specific examples can be cited for determining precipitation, soil moisture, groundwater, snow, surface water and basin characteristics. The application of remote sensing in hydrology can be termed operational if at least one of two conditions are met: (a) the application produces an output on a regular basis,
or (b) the remote sensing data are used regularly on a continuing basis as part of a procedure to solve a problem or make decisions. When surveying the various operational applications, simple approaches and simple remote sensing data sets are the most successful. In the data-sparse developing countries, many operational remote sensing approaches exist (out of necessity) that may not be needed in developed countries because of existing data networks. To increase the use of remote sensing in operational hydrology in developed countries, pilot projects need to be increased and information services must be improved. Increased utilization of GIS to combine remote sensing with other information will promote new products and applications. End user training must be improved by focusing on satellite data processing and manipulation. In developing countries the same improvements are needed plus some more basic ones. There is a need for international monetary assistance to establish long-term remote sensing data, improved database systems
and image processing capabilities. There is also the need to set up innovative regional training centres throughout the developing world.

}, url = {files/bibliography/Rango1998-07.pdf}, author = {A. Rango and Shalaby, Ahlam I.} } @inbook {51287, title = {Outlook for plant invasions: interactions with other agents of global change}, booktitle = {Assessment and management of plant invasions}, year = {1997}, note = {//NONE//LTER-III//ProCite field[6]: In}, month = {1997}, pages = {95-103}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York}, abstract = {

It is the daunting task of this chapter to peer into the future and speculate about the prospects for plant invasion. We know that the globe is changing in its physical, biological, and cultural features. What impact might these changes have on the rate at which plant invaders arrive in our natural communities and on the effect they have there? One can certainly list some of the major changes underway in the environment and review the ways in which the arrival or establishment of invaders might be affected; that is how I will begin. However, it is clearly unwise to think of these factors in isolation from one another, and so I go on to discuss possible synergistic relationships among the factors. I will also try to put into a larger management context the entire issue of plant invasions as affected by global change.

}, keywords = {book, books, chapter, chapters, global change, plant invasion, plant invasion, plant, exotics, report, reports}, url = {files/bibliography/JRN00248.pdf}, author = {L. Huenneke}, editor = {Luken, J. O. and Thieret, J. W.} } @proceedings {51335, title = {An overview of arid grasslands in the northern Chihuahuan Desert}, year = {1996}, month = {October 9-13, 19}, pages = {11-20}, publisher = {USDA Forest Service, Rocky Mountain Research Station}, address = {Tucson, AZ}, abstract = {

The intent of this paper is to outline information on four topics regarding grasslands of the Chihuahuan desert: 1) general aspects of their ecological dimensions, 2) recent vegetation dynamics, 3) current threats, and 4) common ground with other desert grasslands. The Chihuahuan desert is a region of about 350,000 square kilometers. There are at least fifteen different definitions of the boundaries of this desert. Figure 1 is from Schmidt (1979) and its boundaries are based on an aridity index. Generally, this index reflects an area of \<250 mm of average annual precipitation, an average mean annual temperature of 17 C, and an elevation of \> 1200 m. This paper will focus on the northern region of the Chihuahuan desert, an area called the Trans-Pecos which extends from Southeast Arizona across New Mexico into Texas. A small portion of the Trans-Pecos occurs in west Texas on the upper Pecos River below the Guadalupe Mountains. The western border of the Chihuahuan Desert in Arizona is defined by the amount of precipitation occurring during the summer monsoonal months. East of this line in the Sonoran desert \>55\% of the annual precipitation occurs during the summer. West of this line in the Chihuahuan desert \<55\% of the annual precipitation occurs during the summer months.

}, url = {/files/bibliography/617.pdf}, author = {Kris Havstad} } @article {JRN54965, title = {Observations of Snow Crystals using Low-Temperature Scanning Electron Microscopy}, journal = {Scanning: The Journal of Scanning Microscopies}, volume = {17}, year = {1995}, month = {01/1995}, pages = {41-49}, chapter = {41}, abstract = {

\  Low-temperature scanning electron microscopy (SEM) was used to observe precipitation particles commonly known as {\textquotedblleft}snowflakes.{\textquotedblright} The snowflakes were collected in Beltsville, Maryland, at temperature ranging from -6{\textdegree} to +1{\textdegree}C, mounted on SEM stubs, frozen in liquid nitrogen (LN2), and then transferred to a cryosystem mounted on a field-emission SEM. Neither sputter coating with platinum nor irradiation by the electron beam affected their delicate fine structure. SEM observations revealed that snowflakes consisted of aggregations of snow crystals that occurred as hexagonal plates, prismatic columns, needles, and dendrites. In some cases, the snow crystals contained minute surface structures that consisted of rimes, microdroplets, short prismatic columns, and amorphous films. Snow crystals from wet snow, which were collected at temperatures of 0{\textdegree} and +1{\textdegree}C, exhibited varying degrees of metamorphism or melting. The discrete crystalline faces and their sharp intersecting angles were gradually replaced by sinuous surfaces that tended to exhibit more spherical shapes. This study indicates that low-temperature SEM is a valuable technique for studying the formation and metamorphosis of snow crystals. The results suggest that combining low-temperature SEM and x-ray analysis could also provide qualitative elemental information on the nucleation particles of snow crystals as well as on the composition of acid snow

}, keywords = {low temperature, SEM, snow crystal, snowflake}, url = {files/bibliography/Rango1995-03.pdf}, author = {Wegin, William P. and A. Rango and E. R. Erbe} } @proceedings {51649, title = {Organogenesis and shoot-tip multiplication from tissue cultures of Atriplex species}, year = {1989}, month = {1989}, pages = {37-39}, publisher = {USDA Forest Service, GTR-INT 256}, address = {Logan, UT}, abstract = {

Roots and shoots were successfully grown from callus cultures of Atriplex canescens and A.griffithsii in some experiments. Attempts to replicate organogenesis in callus or liquid cultures from these species and in A. acanthocarpa, A. confertifolia, and A. polycarpa were unsuccessful, indicating that specific genetic or cultural requirements were necessary for induction. Shoot-tips were multiplied rapidly after two months in culture from diploid (2x), tetraploid (4x), and hexaploid (6x), plants and from three different collections of 4x populations. Shoot-tip multiplication is a promising method of mass propagation of \ specific genotypes of Atriplex species.

}, url = {/files/bibliography/311.pdf}, author = {J.R. Barrow} } @article {51661, title = {Ovarian cyclicity and serum progesterone and LH in fine-wool ewes supplemented with alfalfa and pinto beans}, journal = {Theriogenology}, volume = {32}, number = {1}, year = {1989}, note = {Reprinted with permission from Elsevier, Copyright {\textcopyright} 1989. (http://www.sciencedirect.com/science/journal/0093691X)}, month = {July 1, 1989}, pages = {149-158}, abstract = {

Effects of season and supplementation on the incidence and rate of ovulation and hormone profiles in multiparous, nonlactating ewes were investigated under range and drylot conditions during anestrus (February through August). Ninety ewes received one of six nutritional treatments: 1) range forage, 2) range forage plus 0.33 kg{\textperiodcentered}hd-1{\textperiodcentered}d-1 pinto beans, 3) 0.45 kg{\textperiodcentered}hd-1{\textperiodcentered}d-1 alfalfa pellets, 4) dry lot plus 1.33 kg{\textperiodcentered}hd-1{\textperiodcentered}d-1 prairie hay only, 5) pinto beans or 6) alfalfa pellets at rates used on the range and prairie hay. Supplemented ewes were heavier (P \< 0.05) than ewes fed range forage or prairie hay during most of the study. Seasonality of ovulation, in terms of incidence and rate, was not affected (P \> 0.40) by supplementation in range ewes. The ovulation rate tended to be highest in prairie hay plus pinto bean drylot ewes in February (P = 0.21) and in prairie hay plus alfalfa pellet and prairie hay plus pinto bean ewes in March (P = 0.13) compared with prairie hay ewes. Generally, seasonality of ovulation was not influenced by supplementation (P \> 0.40). The incidence of ovulation approached zero for drylot ewes in April, May, June and July, while it was 43, 27, 35 and 21\% for range ewes, in those same months. Supplementation did not affect serum progesterone during the estrous cycle. Luteinizing hormone (LH) concentrations were similar (P \> 0.50) among drylot treatment groups before a 50-ug gonadotropin releasing hormone (GnRH) challenge. Pinto bean supplementation enhanced serum LH response to GnRH (P \< 0.10).

}, keywords = {luteinizing hormone, ovulation, progesterone, sheep, supplementation}, doi = {10.1016/0093-691X(89)90531-1}, url = {/files/bibliography/343.pdf}, author = {Hamadeh, S.K. and Clarence V. Hulet and Ross, T.T. and Hallford, D.M.} } @mastersthesis {51856, title = {Oral delivery of placebo baits to free-ranging coyotes in southern New Mexico}, year = {1986}, note = {//??//NONE//}, month = {1986}, pages = {49}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, keywords = {coyote,placebo baits, dissertation, dissertations, theses, thesis}, author = {H. W. Stolzenburg} } @article {51869, title = {The occurrence of hypogeous ascomycete in the northern Chihuahuan Desert}, journal = {Mycologia}, volume = {78}, number = {5}, year = {1986}, note = {//NMSU, USDA//LTER I//Listed in LTER2 proposal as citing LTER1 support//}, month = {1986}, pages = {840-841}, abstract = {

Sporocarps of the hypogeous ascomycete Carbomyces emergens Gilky were collected in the northern Chihuahuan Desert, at the entrance to the Jornada Experimental Range, 25 km NNE of Las Cruces, New Mexico on March 13, 1985. The site consisted of coppiced dunes vegetated with Atriplex canescens (Pursh) Nutt., Prosopis glandulosa Torr., and several spring flowering annuals, Lepidium lasiocarpum Nutt., and Les- querella gordonii (Gray) Wats. The interdune spaces were generally devoid of vegetation. The ascocarps were discovered 2-5 cm below the soil surface in and around recent rodent digs located in the interdune areas. Dried specimens were subsequently discovered on the soil surface (April 10, 1985) in the ecotone between the Larrea tri- dentata (DC.) Cov. and the Bouteloua eriopoda (Torr.) Torr. vegetation zones of the Jorada Long Term Ecological Research site, located on the New Mexico State University college ranch, 15 km north of the original collection area. Ascocarps (FIG. 1) were subglobose, ovoid to irregular (0.5-2.1 x 0.8-2.0 cm diam), cream to honey yellow in color, and produced singularly and in clusters. Glebal mass was white when immature becoming yellowish brown with the mat- uration of the fertile pockets of asci. Flesh of mature specimens turning yellow when cut, otherwise remaining white at maturity. Dried specimens found on the soil surface were as described by Trappe (1979).\ 

}, keywords = {article, articles, ascomycetes,hypogeous, Carbomyces, fungi, Carbomyces, fungi, hypogeous ascomycetes, journal, journals}, doi = {10.1080/00275514.1986.12025331}, url = {files/bibliography/JRN00046.pdf}, author = {J. C. Zak and Walter G. Whitford} } @proceedings {52034, title = {Overview of geology as related to environmental concerns in New Mexico}, year = {1981}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1981}, pages = {1-10}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, abstract = {New Mexico faces a special set of environmental problems associated with rich mineral resources, a dry climate, and vast areas of low population. Complex interactions between geology and environmental concerns involve geologic processes that have adverse effects on human activities, and modern society{\textquoteright}s use of mineral, land, and water resources. Geologic processes include moderate-intensity earthquakes, surface subsidence due to rock dissolution, stream floods, debris flows, and landslides. Geological related human impacts on the environment include surface and subsurface extraction of economic mineral deposits (primarily energy minerals), ground-water development, construction of dams and power plants, disposal of hazardous wastes, and establishment of large-area reserves for military operations and scientific research. Geologists have a major role in helping solve environmental problems resulting from effects of geomorphic processes and development of mineral, water, and land resources. Inventories much be made of these processes and resources in order to put complex process-resource-human interactions in proper space and time perspective. Guidelines can then be formulated for mitigation or prevention of geology-related problems. For example, mined lands need to be reclaimed, cities need to be planned, and sites need to be selected for hazardous-waste disposal. Finally, geologists must clearly present available information on relationships between geology and human concerns. The hallmark of environmental geology should be effective communication with nongeologists.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, environment,geology, geology,environmental concerns, geomorphology, processes, proceeding, proceedings}, author = {J. Hawley and Love, David W.} } @proceedings {52093, title = {Overwintering larvae associated with the stalks of Yucca baccata, Yucca elata and Yucca torreyi in Dona Ana County, New Mexico}, year = {1980}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1980}, pages = {83-90}, publisher = {Centro de Investigacion en Quimica Aplicada}, abstract = {Fifty-three stalks of Yucca baccata, Y. elata and Y. torreyi were examined from Dona Ana County, New Mexico, using a cluster sampling method. One-hundred-and-two larvae representing Lepidoptera, Coleoptera and Hymenoptera, were collected from stalks and pods. The most common larvae were Prodoxus coloradensis and P. quinquepunctellus (Incurvariidae) which represented 64\% of all larvae found. In addition, 50 stalks were put in enclosures in the laboratory for rearing adults; various Lepidoptera, Coleoptera, and parasitic Hymenoptera have emerged. The impact of the larvae in the stalks showed that the stalks were weakened by the excavation tunnels the larvae produced which increases the likelihood that the stalk will fall to the ground where the seeds will scatter. The presence of larvae in the pods probably has little effect of reproductive success as only a few seeds per pod were ever damaged.}, keywords = {abstract, abstracts, Coleoptera, Yucca infloresence, conference, conference proceedings, conferences, Hymenoptera, Yucca infloresence, insect larvae,Yucca, Lepidoptera, Yucca infloresence, proceeding, proceedings, Yucca,insect larvae}, author = {Miles, Nancy Jo} } @article {52300, title = {Oxygen consumption of two species of Pogonomyrmex harvester ants (Hymenoptera: Formicidae)}, journal = {Comparative Biochemistry and Physiology}, volume = {46A}, year = {1973}, note = {//LOCAL//US-IBP//}, month = {1973}, pages = {605-611}, abstract = {1. The effects of temperature and vapour pressure deficit (VPD) on oxygen consumption in two species of harvester ants, Pogonomyrmex rugosus and P. maricopa, were evaluated. 2. P. maricopa had a higher rate of oxygen consumption per unit weight than P. rugosus. 3. Higher VPD resulted in an increase in oxygen consumption in P. rugosus but had no significant effect on the oxygen consumption rate in P. maricopa. 4. The increased rate of oxygen consumption in P. rugosus at high VPD was not the result of increased activity.}, keywords = {ant, Pogonomyrmex, article, articles, harvester ant, SEE , journal, journals, Pogonomyrmex, physiology}, author = {George Ettershank and Walter G. Whitford} } @article {52379, title = {Oxygen consumption and water metabolism in a carnivorous mouse}, journal = {Comparative Biochemistry and Physiology}, volume = {40A}, year = {1971}, note = {//LOCAL//NONE//}, month = {1971}, pages = {797-803}, abstract = {

1. Unlike most desert rodents, grasshopper mice, Onychomys torridus, exhibited not reduction in basal metabolic rate from that predicted for mice their size and had high pulmocutaneous water loss.

2. Their thermal neutral zone was 30-35 C.

3. Fecal and urinary water losses were a function of water intake.

4. Food intake increased with water deprivation and the mice could maintain their weight on a beef liver diet containing 72\% water.

5. Data from this study suggest that problems of water balance in this species are most severe in winter.

}, keywords = {article, articles, journal, journals, metabolism,Onychomys, Onychomys,physiology, physiology,Onychomys, rodent, grasshopper mouse,Onychomys, rodent,metabolism, rodent,Onychomys}, doi = {10.1016/0300-9629(71)90265-9}, url = {files/bibliography/71-CompBiochemistry\&Physlogy-Whitford.pdf}, author = {Walter G. Whitford and Marsha R. Conley} } @mastersthesis {52396, title = {Occurrence of vegetation and emergence of species from surface soil collected on two southwestern desert range sites}, year = {1970}, note = {//NMSU//NONE//}, month = {1970}, pages = {30}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {The main objective of this study was to determine the number and species of plants that emerged from the surface two centimeters of soil collected from three locations: 1) under the canopy of creosotebush plants; 2) form open areas dominated by creosotebush but outside the canopy of the plants; and, 3) from a mesquite dominated site. Also species present on the sites in the field were compared with those species emerging from collected soil in the greenhouse under different soil moisture levels.... For each of the three locations the total number of different species found on the sites was higher than the number of species emerging form the collected soil. No mesquite plants emerged in soil collected from mesquite location or either of the creosotebush locations; nor did any creosotebush plants emerge in soil collected from the mesquite site.}, keywords = {creosotebush, germination, dissertation, dissertations, mesquite, germination, seedling germination, theses, thesis}, author = {Nava, Guillermo} } @proceedings {52425, title = {Opal phytoliths in Bouteloua eriopoda Torr. roots and soils}, volume = {33}, year = {1969}, note = { //USDA,OTHER//NONE//entered 06/29/2009; pdf availableProCite field[6]: In}, month = {January 22-26, 1}, publisher = {Soil Science Society of America Proceedings}, address = {Riverside, CA}, abstract = {

Identification of phytoliths from Bouteloua eriopoda Ton. (black grama) roots was based on repetitive size and shape, low density, acid insolubility, and lack of crystallinity. Refractive index, and contents of water and SiO2 support identification as opal. These distinctive rectangular phytoliths were the most commonly observed form in the A horizons of several soils and paleosols.

}, keywords = {abstract, article, Bouteloua eriopoda, conference, phytolith, proceedings}, author = {D. S. Pease and J. U. Anderson} } @mastersthesis {52451, title = {Opal phytoliths as indicators of paleosols}, year = {1967}, note = {//USDA,OTHER//NONE//entered 06/29/2009ProCite field[12]: Not in File (06/29/2009)}, month = {1967}, pages = {81}, school = {New Mexico State University}, type = {M.S. Thesispp}, address = {Las Cruces, New Mexico}, abstract = {Research was conducted to assess the usefulness of opal phytoliths (1) to identify paleosols and 2) to recreate vegetative histories and paleoclimates. Specimens of phytoliths were collected from five grass, five shrub, and three conifer species. The results show significant quantities of phytoliths from the aboveground portions of the grasses and black grama roots. There were smaller quantities of phytoliths in roots of other grasses, in yucca leaves, and in the conifer needles. Phytoliths were nearly lacking in the other shrubs. The occurrence of phytoliths was studied in the A horizons of six soils and in several horizons of four paleosols. The quantity of phytoliths in the A horizons ranged from 0.008 to 0.031 percent by weight. The quantity of phytoliths in the paleosols was small ranging from a trace to 0.001 percent. Wind movement and solution of clay size phytoliths, partial solution of larger phytoliths and mixing or the removal of the A horizons during deposition of new sediments are suggested as the causes of the paucity of phytoliths in paleosols.}, keywords = {Bouteloua eriopoda, dissertation, Ephedra trifurca, Hilaria mutica, Larrea, Muhlenbergia porter, Opuntia leptocaulis, Opuntia phaeacantha, paleosols, phytolith, Pinus edulis, Pinus ponderosa, Pleuraphis mutica, Scleropogon brevifolius, Sporobolus flexuosus, thesis, Yucca elata}, url = {NMSU Library System: Call no: S 1999 .P42 1967}, author = {D. S. Pease} } @article {52458, title = {Observations on territoriality and aggressive behavior in the western spadefoot toad (Scaphiopus hammondii)}, journal = {Herpetologica}, volume = {23}, number = {4}, year = {1967}, note = {//LOCAL//NONE//}, month = {1967}, pages = {318}, abstract = {

On 7 June 1967 I had an opportunity to observe the spacing of calling males and aggressive behavior in the western spadefoot toad, Scaphiopus hammondii, while collecting in a flooded pecan grove in Las Cruces, Dona Ana Co., N. M. Soon after entering the grove where a large number of S. hammondii were calling, it was apparent that the distribution of calling males was not random. The rows of pecan trees formed a natural grid which simplified observations of the distribution of calling males. Three or four males called in an area of approximately 440 square feet circumscribed by pecan trees in the corners. The toads were separated from each other by at least 10 feet.

}, keywords = {amphibian, also SEE , anuran, Scaphiopus, anuran,behavior, article, articles, behavior, Scaphiopus, behavior,also SEE , journal, journals, Scaphiopus,behavior}, url = {files/bibliography/67-Herp-Whitford.pdf}, author = {Walter G. Whitford} } @article {52609, title = {The occurrence of Gutierrezia sarothrae on Bouteloua eriopoda ranges in southern New Mexico}, journal = {Ecology}, volume = {15}, number = {1}, year = {1934}, month = {January 1934}, pages = {49-61}, abstract = {Bouteloua eriopoda Torr. (black grama) is characteristic of the desert plains association described by Weaver and Clements ({\textquoteright}29) and extends from southwestern Texas through southern New Mexico, Arizona and northern Mexico. This grass, if not depleted, is the most abundant and valuable forage species on the well-drained sandy or gravelly soils of dry mesas in the region, especially in southern New Mexico. Jardine and Forsling ({\textquoteright}22) have shown that continued overgrazing of Bouteloua eriopoda range leads to deterioration of the valuable grasses and the establishment of Gutierrezia spp. (snakeweed or broomweed) accompanied by reductions in grazing capacity and loss of soil stability. The ultimate result of continued injudicious grazing may be a transformation of the Bouteloua range to the Prosopis (mesquite) sand dune scrub association. Periodic drought is partly responsible for the deterioration because of the wide spacing of plants resulting from low rainfall and the facility with which the range is overgrazed when inadequate precipitation causes poor forage production. Many ranchmen believe that Gutierrezia will crowd out the valuable forage grasses on the range. This opinion results from failure to recognize over-utilization and ignoring the fact that on grass ranges, the unpalatable Gutierrezia plants are subject to little foliage removal by cattle, while the palatable grasses, when overutilized, sometimes are eaten to within half an inch of the soil surface. In order to determine the trend of Gutierrezia occurrence in the Bouteloua eriopoda association and to establish its significance in plant succession, a study of the problem was initiated. The work upon which this paper is based was done near Las Cruces, New Mexico, on the Jornada Experimental Range, a branch of the Southwestern Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture.}, keywords = {Bouteloua eriopoda, deterioration, Gutierrezia sarothrae, occurrence, overgrazing, plant succession}, url = {/files/bibliography/025.pdf}, author = {R.S. Campbell and Bomberger, E.H.} }