Improving the understanding and scaling of land-atmosphere carbon, water and energy exchange in a Chihuahuan Desert shrubland at the Jornada Experimental Range, Southern New Mexico.

Arid and semiarid ecosystems represent about 40% of the world’s land cover and are home of about 35% of the world’s human population. However, over the last century arid and semiarid regions have increasingly been affected by desertification and in many regions, vegetation has shifted from grassland to shrubland dominated ecosystems.  Recent studies suggest that this land cover change increases albedo and latent heat flux, which increases near surface air temperature. Although the extent of desertified landscapes are expected to expand over the next 30 to 40 years, there is a relatively poor understanding of how the transition to this new system state will impact ecosystem function and feedbacks to other components of the earth system such as the atmosphere. Key to addressing this challenge is an improved understanding of ecosystem dynamics and land-atmosphere interactions at the landscape scale and a capacity to extrapolate dynamics to regional scales using remote sensing. This study addresses both the scientific and technical aspects of the above challenges to improve i) the understanding of carbon,  water and energy budgets in a desert shrubland, and ii) Cyberinfrastructure that facilitates long term and synthesis studies  contributing to national and international networks such as AMERIFLUX and FLUXNET. The study site is located in the southeastern portion of the USDA ARS Jornada Experimental Range (JER), located about 25 km northeast of Las Cruces, New Mexico, USA. The region is dominated by a mixed creosote bush (Larrea tridentata) – honey mesquite (Prosopis glandulosa) shrubland. Other species include tarbush (Flourencia cernua), the grass bush muhly (Muhlenbergia porter), fluff grass (Dasyochloa pulchella), and black grama (Bouteloa eripoda), as well as a variety of forbs. The shrub average canopy height is approximately 2.0 m, and soils are classified as Ustic Calciargids. The experimental design includes an extended open path eddy covariance system, a hyperspectral reflectance tramline with automatic cart, a sensor network, a network of four phenocams, and plot phenology measurements. Results of this study will emphasize the relationship between seasonal patterns of net ecosystem exchange, phenology and vegetation and landscape spectral indices. The present study is being completed through an interdisciplinary collaboration within the University of Texas at El Paso’s (UTEP) Cyber-ShARE Center with the support of the Jornada Experimental Range (JER) and Jornada Long Term Ecological Research Program (JRN).