@conference {JRN55425, title = {Participatory research and co-production of knowledge: Building on a century of Jornada experience to expand LTAR outcomes and impacts}, booktitle = {LTAR Annual Meeting}, year = {2021}, abstract = {The co-production of knowledge with stakeholders is a unique strength of the Agricultural Research Service. The objective of this poster is to share examples of how co-production has been successfully applied to achieve four very different sets of objectives with national to global impact: (1) developing standardized rangeland indicators and monitoring methods; (2) developing interpretive tools; (3) identifying research gaps and needs for tools and new indicators (e.g., AERO, phenology) to inform conservation planning; and (4) building understanding of management technologies and systems to meet stakeholder land use goals. Collaborative research examples include work with the Malpai Borderlands Group, the BLM{\textquoteright}s {\textquotedblleft}Restore New Mexico{\textquotedblright} program, the development and implementation of BLM AIM and NRCS NRI national inventory and monitoring programs, NRCS CEAP-Grazing Lands model development (AERO; RHEM) and data processing (Landscape Data Commons) for effects assessments of NRCS conservation practices, the Sustainable Southwest Beef Coordinated Agricultural Project, and the development of LandPKS and EDIT. Our approach to co-production is iterative and results from a 25+ year series of diverse engagement approaches (trainings, working groups, day-to-day involvement), which has led to directly applicable research and management tools. Current LTAR efforts, including the Jornada Common Experiment and those of the LTAR Rangeland Soil Erosion, Wind Erosion, Phenology, and Indicators Working Groups, provide opportunities to expand these long-term participatory research and co-production efforts to improve and extend LTAR research impacts. This poster illustrates lessons learned from the Jornada experience and highlights opportunities for broader collaboration across the LTAR network.}, keywords = {building, century, co-production, impacts, Jornada, Long-Term Agricultural Research outcomes, LTAR, Participatory, research}, author = {Sarah McCord and Brandon T Bestelmeyer and Dawn M. Browning and Laura M. Burkett and Brandon Edwards and Jeffrey E. Herrick and Emily Kachergis and Nika Lepak and Leticia Lister and Loretta Metz and Terri Schulz and S. Spiegal and Nicholas Webb} } @article {49865, title = {Density fractionation and 13C reveal changes in soil carbon following woody encroachment in a desert ecosystem}, journal = {Biogeochemistry}, volume = {112}, year = {2013}, month = {03/2013}, pages = {409-422}, chapter = {409}, abstract = {Woody encroachment has dramatically changed land cover patterns in arid and semiarid systems (drylands) worldwide over the past 150 years. This change is known to influence bulk soil carbon (C) pools, but the implications for dynamics and stability of these pools are not well understood. Working in a Chihuahuan Desert C4 grassland encroached by C3 creosote bush (Larrea tridentata), we used two density fractionation techniques (2 and 7 pool density fractionations) and isotopic analysis to quantify changes in C pools and dynamics among vegetation microsites typical of an encroachment scenario (remnant intact grassland, shrub subcanopies, and in shrub intercanopy spaces within a shrubencroached area). The C concentration of bulk soils varied with microsite, with almost twice the C in shrub subcanopies as in intercanopy spaces or remnant grasslands. Estimated SOC accumulation rates from Larrea encroachment (4.79 g C m-2 year-1 under canopies and 1.75 g C m-2 year-1 when intercanopy losses were taken into account) were lower than reported for higher productivity Prosopis systems, but still represent a potentially large regional C sink. The composition of soil C varied among microsites, with the shrub subcanopy C composed of proportionally more light fraction C (\1.85 g cm-3) and C that was soluble in sodium polytungstate. Grassland soils contained very little carbonate C compared to shrub subcanopies or shrub intercanopy spaces. Stable isotope analyses indicate that inputs from C3 shrubs were incorporated into all density fractions, even in heavy fractions in which shrub inputs did not change overall C concentration. The seven density fractionation yielded unexpected \ð13C patterns, where the two heaviest fractions were strongly depleted in 13C, indicating strong fractionation following organic matter inputs. These results suggest that the utility of isotope mixing models for determining input sources may be limited in systems with similar fractionation patterns. We propose a five pool model for dryland soil C that includes a relatively dynamic light fraction, aggregate and heavy fractions that are stable in size but that reflect dynamic inputs and outputs, a potentially large and seasonally dynamic pool of soluble C, and a large pool of carbonate C. Combined, these results suggest that dryland soil C pools may be more dynamic than previously recognized.}, keywords = {black grama grass, Bouteloua, carbonates, creosotebush, dryland, Jornada, Larrea, soil carbon stabilization, soil organic matter, woody encroachment}, doi = {10.1007/s10533-012-9735-y}, url = {/files/bibliography/13-020.pdf}, author = {Heather L. Throop and Kate Lajtha and Kramer, Marc} } @article {49872, title = {Soil coverage reduces photodegradation and promotes the dvelopment of soil-microbial films on dryland leaf litter}, journal = {Ecosystems}, volume = {15}, year = {2012}, pages = {311-321}, chapter = {311}, abstract = {

Litter decomposition is a central focus of ecosystem science because of its importance to biogeochemical pools and cycling, but predicting dryland decomposition dynamics is problematic. Some studies indicate photodegradation by ultraviolet (UV) radiation can be a significant driver of dryland decomposition, whereas others suggest soil{\textendash}litter mixing controls decomposition. To test the influence of soil coverage on UV photodegradation of litter, we conducted a controlled environment experiment with shrub (Prosopis velutina) leaf litter experiencing two UV levels and three levels of coverage with dry sterile soil. Under these conditions, decomposition over 224 days was enhanced by UV, but increasing soil coverage strongly and linearly diminished these effects. In a complementary study, we placed P. glandulosa leaf litter in different habitats in the field and quantified litter surface coverage by soil films. After 180 days, nearly half of the surface area of litter placed under shrub canopies was covered by a tightly adhering film composed of soil particles and fungal hyphae; coverage was less in grassy zones between shrubs. We propose a conceptual model for the shifting importance of photodegradation and microbial decomposition over time, and conclude that (1) soil deposition can ameliorate the direct effects of UV photodegradation in drylands and (2) predictions of C losses based solely on UV effects will overestimate the importance of this process in the C cycle. An improved understanding of how development of the soil{\textendash}litter matrix mediates the shift from abiotic (photodegradation) to biotic (microbial) drivers is necessary to predict how ongoing changes in land cover and climate will influence biogeochemistry in globally extensive drylands.

}, keywords = {carbon cycle, decomposition, dryland, Jornada, litter, mesquite, photodegradation, Prosopis, soil erosion, soil-litter mixing, soil-microbial films, ultraviolet radiation}, doi = {10.1007/s10021-011-9511-1}, url = {/files/bibliography/12-019.pdf}, author = {Barnes, Paul W. and Heather L. Throop and Hewins, Daniel B. and Abbene, Michele L. and Steven R. Archer} } @article {49881, title = {Animal foraging as a mechanism for sediment movement and soil nutrient development: Evidence from the semi-arid Australian woodlands and the Chihuahuan Desert}, journal = {Geomorphology}, volume = {157-158}, year = {2012}, month = {01/01/2012}, pages = {131-141}, chapter = {131}, abstract = {

An emerging area of interest in geomorphology over the past two decades has been the effects of biota on ecosystemprocesses.We examined the roles of a rangeof vertebrates on soil disturbance in two markedly different environments, the semi-arid woodland of eastern Australia and a Chihuahuan Desert grassland{\textendash}shrubland in the south-western United States. Foraging pits of soil-disturbing vertebrates varied markedly from small scratchings of heteromyid (mainly Dipodomys spp.) rodents (1.8{\texttimes}10-4m3) to deep (1.0{\texttimes}10-2 m3) excavations of the burrowing bettong (Bettongia leuseur) and greater bilby (Macrotis lagotis). Vertebrates moved substantial volumes of soil in both environments, and activity was highly temporally and spatially variable. At large spatial scales, soil disturbance by echidnas (Tachyglossus aculeatus) and Gould{\textquoteright}s sand goannas (Varanus gouldii) was substantially greater in communities dominated by shrubs, and where domestic livestock had been excluded. Heteromyid rodents tended to excavate more foraging pits in coarse-textured vegetation communities (both grasslands and shrublands). In both environments, foraging was concentrated close to perennial plants such as grass tussocks and tree canopies rather than in the interspaces. Foraging pits of Chihuahuan desert animals tended to be higher in labile carbon and support greater levels of infiltration, though this was plant community-dependent. Overall our results indicate that animal foraging is an important geomorphic mechanism capable of mobilizing substantial volumes of soil in arid and semi-arid environments and with potential effects on soil function. {\textcopyright} 2011 Elsevier B.V. All rights reserved.

}, keywords = {arid, Australia, Biopedturbation, foraging, Jornada, patchiness, rodents, soil formation, soil movement, vertebrates}, doi = {10.1016/j.geomorph.2011.04.041}, url = {/files/bibliography/12-016.pdf}, author = {D.J. Eldridge and T. B. Koen and Aaron Killgore and Huang, Niki and Walter G. Whitford} } @article {49891, title = {An accounting of C-based trace gas release during abiotic plant litter degradation}, journal = {Global Change Biology}, volume = {18}, year = {2012}, pages = {1185-1195}, abstract = {

Recent studies showed that photochemical breakdown (photodegradation) of plant material accounts for a substantial portion of litter decomposition and subsequent trace gas release in ecosystems under high radiative load and low precipitation. In the absence of solar radiation, thermal degradation may also cause trace gas release at temperatures below the ignition point. These observations suggest that the abiotic processes of photodegradation and thermal degradation of plant litter may be important in understanding global trace gas budgets. In a laboratory incubation study, we performed a simultaneous carbon (C) accounting of CO2, CO, and CH4 produced as a byproduct of photodegradation and thermal degradation of six different plant litter types that varied in chemical composition. The patterns of trace gas release during photodegradation and thermal degradation differed considerably across the six plant materials, suggesting that chemical composition of litter may influence the rates of abiotic degradation. There was a strong positive correlation between the rates of trace gas release during photodegradation and temperature. A significant portion of trace gases were produced during low temperature (\<\ 100\ {\textdegree}C) thermal degradation of litter in the absence of solar radiation, which was also positively correlated to temperature. In addition, both thermal degradation and photodegradation occurred in the absence of O2. This indicates that the mechanism formerly accepted as photo-oxidation may only be one of several photodegradation processes. We speculate that the direct breakdown of chemical groups such as carboxyl, carbonyl, and methoxyl groups may result in CO2, CO, and CH4 release. We suggest that the combined processes of thermal and photodegradation of litter may be a previously under accounted source of C-based trace gases from terrestrial systems.

}, keywords = {carbon dioxide, carbon monoxide, carbon-based trace gas, CH4, CO, CO2, decomposition, Jornada, litter decomposition, methane, photodegradation, plant litter, thermal degradation}, doi = {10.1111/j.1365-2486.2011.02579.x}, url = {files/bibliography/JRN00590.pdf}, author = {Hanna Lee and Rahn, Thom and Heather L. Throop} } @article {49909, title = {Response of dominant grass and shrub species to water manipulation: An ecophysiological basis for shrub invasion in a Chihuahuan Desert grassland}, journal = {Oecologia}, volume = {169}, year = {2012}, month = {01/15/2012}, pages = {373-383}, chapter = {373}, abstract = {Increases in woody vegetation and declines in grasses in arid and semi-arid ecosystems have occurred globally since the 1800s, but the mechanisms driving this major land-cover change remain uncertain and controversial. Working in a shrub-encroached grassland in the northern Chihuahuan Desert where grasses and shrubs typically differ in leaf-level nitrogen allocation, photosynthetic pathway, and root distribution, we asked if differences in leaflevel ecophysiology could help explain shrub proliferation. We predicted that the relative performance of grasses and shrubs would vary with soil moisture due to the diVerent morphological and physiological characteristics of the two life-forms. In a 2-year experiment with ambient, reduced, and enhanced precipitation during the monsoon season, respectively, the encroaching C3 shrub (honey mesquite Prosopis glandulosa) consistently and substantially outperformed the historically dominant C4 grass (black grama Bouteloua eriopoda) in terms of photosynthetic rates while also maintaining a more favorable leaf water status. These differences persisted across a wide range of soil moisture conditions, across which mesquite photosynthesis was decoupled from leaf water status and moisture in the upper 50 cm of the soil proWle. Mesquite\’s ability to maintain physiologically active leaves for a greater fraction of the growing season than black grama potentially ampliWes and extends the importance of physiological differences. These physiological and phenological differences may help account for grass displacement by shrubs in drylands. Furthermore, the greater sensitivity of the grass to low soil moisture suggests that grasslands may be increasingly susceptible to shrub encroachment in the face of the predicted increases in drought intensity and frequency in the desert of the southwestern USA.}, keywords = {drought, grassland community, Jornada, photosynthesis, precipitation manipulation, shrub invasion, water manipulation, water potential, woody encroachment}, doi = {10.1007/s00442-011-2217-4}, url = {/files/bibliography/12-015.pdf}, author = {Heather L. Throop and Lara Reichmann and O. E. Sala and Steven R. Archer} } @article {JRN54005, title = {Detecting land cover change at the Jornada Experimental Range, New Mexico with ASTER emissivities}, journal = {Remote Sensing of Environment}, volume = {112}, year = {2008}, month = {04/2008}, pages = {1730-1748}, chapter = {1730}, abstract = {

Multispectral thermal infrared remote sensing of surface emissivities can detect and monitor long term land vegetation cover changes over arid regions. The technique is based on the link between spectral emissivities within the 8.5\–9.5\ \μm interval and density of sparsely covered terrains. The link exists regardless of plant color, which means that it is often possible to distinguish bare soils from senescent and non-green vegetation. This capability is typically not feasible with vegetation indices. The method is demonstrated and verified using ASTER remote sensing observations between 2001 and 2003 over the Jornada Experimental Range, a semi-arid site in southern New Mexico, USA. A compilation of 27 nearly cloud-free, multispectral thermal infrared scenes revealed spatially coherent patterns of spectral emissivities decreasing at rates on the order of 3\% per year with R2 values of \∼\ 0.82. These patterns are interpreted as regions of decreased vegetation densities, a view supported by ground-based leaf area index transect data. The multi-year trend revealed by ASTER\&$\#$39;s 90-m resolution data are independently confirmed by 1-km data from Terra MODIS. Comparable NDVI images do not detect the long-term spatially coherent changes in vegetation. These results show that multispectral thermal infrared data, used in conjunction with visible and near infrared data, could be particularly valuable for monitoring land cover changes.

}, keywords = {ASTER, emissivity, Jornada, land cover change, MODIS, Thermal infrared}, doi = {10.1016/j.rse.2007.08.020}, author = {A.N. French and T. J. Schmugge and Jerry Ritchie and A.F. Hsu and Jacob, F. and Ogawa, K.} } @article {50247, title = {Spatial variability of soil and nutrient characteristics of semi-arid grasslands and shrublands, Jornada Basin, New Mexico}, journal = {Ecohydrology}, volume = {1}, year = {2008}, note = {//USDA//LTER-V//entered 06/02/2008; PDF on file}, month = {2008}, pages = {3-12}, abstract = {

Heterogeneity of vegetation and soil properties is characteristic of semi-arid and arid environments. The potential underlying causes of the dynamics that create this spatial variability, with consequent impacts on landscape connectivity and thus ecological and ecohydrological processes, are not clearly understood. An investigation was carried out into the spatial variability of ponded infiltration rate, soil moisture, soil-aggregate stability, vegetation cover, random roughness and nutrient content in the soil (ammonium, nitrate and phosphorus) at grassland and shrubland sites for two spatial scales in the Jornada Basin, in the northern part of the Chihuahua desert. At the plant-interplant scale, statistically significant differences exist between vegetated and non-vegetated sites for soil moisture and infiltration rate within both shrublands and grasslands. The spatial distributions of all other parameters follow a more complex scheme at this scale. At the landscape scale, distinct differences exist for most parameters between the grasslands and the shrubland sites. Geostatistical analysis revealed that the autocorrelation lengths are not simply a function of average shrub sizes, but may be caused by a more complex pattern probably related to the spatial layout of rill and inter-rill areas and other localized transfers of soil resources through the redistribution of water and wind. These results demonstrate the importance of understanding spatial linkages of processes within the landscape in understanding dryland ecosystem dynamics. Copyright {\textcopyright} 2007 John Wiley \& Sons, Ltd.

}, keywords = {article, connectivity, desert ecosystems, desertification, grassland, hydrology, Jornada, Jornada Basin, journal, landscape ecology, shrubland, soil characteristics, spatial variability, soil nutrients, spatial variability, spatial variability}, doi = {10.1002/eco.1}, url = {files/bibliography/JRN00515.pdf}, author = {Eva N. M{\"u}ller and John Wainwright and A.J. Parsons} } @inbook {50446, title = {Water and energy balances within the Jornada Basin}, booktitle = {Structure and Function of a Chihuahuan Desert Ecosystem. The Jornada Basin Long-Term Ecological Research Site}, year = {2006}, month = {July 1, 2006}, pages = {176-188}, publisher = {Oxford University Press}, organization = {Oxford University Press}, chapter = {8}, address = {New York}, abstract = {This chapter describes general characteristics and components of the energy and water balances in arid regions, with specific examples from the Jornada Basin. Various research efforts to characterize the energy and water balances and resultant carbon dioxide fluxes in the Jornada Basin are detailed. We provide a brief overview of how plant physiology interacts with energy and water balances in this region. The purpose of this chapter is to characterize the general abiotic conditions and some physiological traits of plants in this semiarid region.}, keywords = {arid, balances, carbon, dioxide, energy, Jornada, regions, water}, url = {/files/bibliography/06-059.pdf}, author = {V. P. Gutschick and K. A. Snyder}, editor = {Kris Havstad and L. Huenneke and W. H. Schlesinger} } @inbook {50502, title = {Nutrient cycling within an arid ecosystem}, booktitle = {Structure and Function of a Chihuahuan Desert Ecosystem. The Jornada Basin Long-Term Ecological Research Site}, year = {2006}, month = {July 1, 2006}, pages = {133-149}, publisher = {Oxford University Press}, organization = {Oxford University Press}, chapter = {6}, address = {New York, NY}, abstract = {In arid and semiarid lands, soil erosion by wind is an important process that affects both the surface features and the biological potential of the ecosystem. The eolian flux of soil nutrients into or out of an ecosystem results in enrichment or impoverishment of its biological potential. In the Jornada Basin, wind erosion is the only significant mechanism for the net loss of soil materials because fluvial processes do not remove materials from the basin. Vigorous wind erosion leads to topographic changes, altering the growing conditions for plants and animals. Examples of such changes in topography are the formation of sand dunes or the removal of whole soil horizons. Our goal in this chapter is to describe the construction of a mathematical model for wind erosion and dust production for the Jornada Basin. The model attempts to answer the following questions:1. Which soils are affected by wind erosion?2. How does wind erosion occur on Jornada soils?3. Does changing vegetation cover lead to a change in the source/sink relationship? 4. Is the Jornada a source or sink of eolian materials? If it is a source, what materials are lost?5. How does wind erosion change the soil-forming process?}, keywords = {cycling, erosion, Jornada, nutrient, semiarid, soil}, url = {/files/bibliography/06-057.pdf}, author = {W. H. Schlesinger and S. Tartowski and Schmidt, S.M.}, editor = {Kris Havstad and L. Huenneke and W. H. Schlesinger} } @article {50988, title = {Root systems of some Chihuahuan Desert plants}, journal = {Journal of Arid Environments}, volume = {49}, number = {2}, year = {2001}, month = {October 1, 2001}, pages = {221-263}, abstract = {Root systems of 11 shrub or shrub-like species, 11 grass species, 19 perennial forb species and 4 annual forb species were excavated on the Jornada Experimental Range in the northern Chihuahuan Desert in southern New Mexico, USA. Maximum radial horizontal spread of shrub root systems usually occurred above calcic and petrocalcic horizons at depths above 1 m. .With one exception, all shrub species roots were traced through calcic and petrocalcic horizons to depths down to 5 m. Upward growing roots reaching very shallow depths (\< 10 cm) were common for most shrub species. Thus, the shrubs can readily access soil water and nutrients from both surface and deep soil horizons. Grass root systems on sandy soils extended radially up to 1.4 m, perhaps an adaptation to capture more soil water from the frequent small rainfall events. Grass roots did not extend through calcic or petrocalcic horizons and none penetrated deeper than 1.6 m. Perennial forb root systems varied in depth of branching but often penetrated into o through calcic and petrocalcic horizons and, like shrubs, have an advantage over grasses during droughts. Root systems of the annual forbs, excavated at the end of a season of above average precipitation, reached depths of 0.5 to 1.2 m. At each of the 18 excavation sites the roots of all the plant life forms were highly intermingled in the upper soil horizons, indicating that competition for water and soil nutrients is intense. It is believed that the plasticity and architecture of the shrub root systems, enabling them to compete with the grasses for soil water in the upper soil horizons and also access soil water at depths beyond the reach of grass roots, has been a major reason for the increase of shrubs during the historical period in this arid environment.}, keywords = {Chihuahuan Desert, competition, forbs, grasses, Jornada, root systems, shrubs, soil resources}, doi = {10.1006/jare.2000.0784}, url = {/files/bibliography/01-023.pdf}, author = {Gibbens, Robert P. and J.M. Lenz} } @proceedings {51117, title = {Estimation of surface emissivity for arid lands}, volume = {IAHS Publication No. 267}, year = {2000}, month = {2001}, pages = {168-174}, publisher = {Remote Sensing and Hydrology}, address = {Santa Fe, NM}, abstract = {

Knowledge of surface emissivity is important for determining the radiation balance at the land surface. For heavily vegetated surfaces there is little problem since the emissivity is relatively uniform and close to one. For arid lands with sparse vegetation the problem is more difficult because the emissivity of the exposed soils and rocks is highly variable. With multispectral thermal infrared (TIR) observations it is possible to estimate the spectral emissivity variation for these surfaces. The data presented is from the TIMS (Thermal Infrared Multispectral Scanner) instrument which has six channels in the 8 to 12 {\textmu}m region. TIMS is a prototype of the TIR portion of the ASTER (Advanced Spaceborne Thermal Emission and Reflection radiometer) instrument on NASA{\textquoteright}s EOS-TERRA satellite. The approach is to use the Temperature Emissivity Separation (TES) algorithm developed for use with ASTER data to extract the temperature and six emissivities from the six channels of TIMS data. The algorithm makes use of the empirical relation between the range of observed emissivities and their minimum value. This approach was applied to the TIMS data acquired over the USDN ARS Jornada Experimental Range in New Mexico. The Jornada site is typical of a desert grassland where the main vegetation components are grass (black grama) and shrubs (primarily mesquite) in the degraded grassland. The data are from an altitude of 800 m yielding a pixel resolution of approximately 2 m. The result-ing spectral emissivities are in qualitative agreement with laboratory measurements of the emissivity (E) for the quartz rich soils of the site with{\textsterling}\< 0.8 for the 8-9.5 {\textmu}m channels. For the longest wavelength channel little spatial variation of{\textsterling} was observed with values of0.96 {\textpm} 0.005 over large areas.

}, keywords = {arid lands, ASTER, Chihuahuan Desert, emissivity, Jornada, multispectral, surface temperature, Thermal infrared, TIMS}, url = {/files/bibliography/01-081.pdf}, author = {T. J. Schmugge and A.N. French and Jerry Ritchie and A. Rango} } @article {52282, title = {Primary production on the Jornada site for 1972}, year = {1974}, month = {1974}, pages = {29}, institution = {International Biological Program, Grassland Biome Technical Report 249}, keywords = {Jornada, popular publication, production}, author = {Pieper, Rex D. and C.H. Herbel} }