96th ESA Annual Meeting (August 7 -- 12, 2011)

COS 108-9 - Monitoring climate variability and change along two elevation gradients in the Mojave and Great Basin Deserts

Thursday, August 11, 2011: 4:20 PM
6A, Austin Convention Center
Lynn F. Fenstermaker1, Dale A. Devitt2, Laurel S. Saito3, John A. Arnone III4, Franco Biondi5, Brett R. Riddle2, Mark J. Walker3, Richard L. Jasoni4, Scotty Strachan5, Brian Bird2, Greg McCurdy6 and Brad Lyles7, (1)Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, NV, (2)School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, (3)Department of Natural Resources and Environmental Science, University of Nevada, Reno, Reno, NV, (4)Division of Earth and Ecosystem Sciences, Desert Research Institute, Reno, NV, (5)DendroLab, Dept. of Geography, University of Nevada, Reno, NV, (6)Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, (7)Division of Hydrological Sciences, Desert Research Institute, Reno, NV
Background/Question/Methods

The Nevada System of Higher Education received a grant from the National Science Foundation’s Experimental Program to Stimulate Competitive Research (EPSCoR to create a statewide interdisciplinary collaboration that will stimulate transformative research, education, and outreach about the effects of regional climate change on ecosystem services (particularly water resources). The overarching question this effort is addressing is: how will climate change affect water resources, disturbance regimes and linked ecosystem and human services? This presentation focuses on the ecology and water resources components, and specifically addresses the results of our first measurements from two transects of monitoring stations. The two transects cross elevation gradients in both the Mojave and Great Basin Deserts. The monitoring stations are being established to enable assessment of present-day climate variability within key vegetation zones associated with specific ranges in elevation. The standard suite of sensors include: Geonor and tipping bucket precipitation; ultra-sonic snow depth, solar radiation, net radiation, photosynthetically active radiation, multi-height air temperature, relative humidity, barometric pressure, wind speed/direction, soil moisture at the surface (DPHP) and at depth (TDR), soil water matric potential, small diameter piezometers, surface runoff, soil heat flux, soil temperature, sap flow and point dendrometers for key species, and PTZ web cameras.

Results/Conclusions

The two transects established in the Mojave and Great Basin Deserts are the first monitoring stations located along an elevation gradient providing critical climatic, soil and vegetation data for key vegetation zones. Results to date document increased precipitation with increasing elevation; a 47% increase in cumulative precipitation between the sagebrush and montane sites was observed and a 19% increase in cumulative precipitation between the montane and subalpine sites occurred during the measurement period. Photosynthetically active radiation (PAR) follows the same diurnal time course for all sites within a transect, however the subalpine site has a 5% increase in the peak hourly average PAR in comparison to the lower elevation sites. During periods when clouds covered all sites, the sagebrush site, followed by the montane site, typically had higher hourly average PAR values than the subalpine site. Some of the more interesting results to date come from a comparison of air temperature across the elevation gradient. There are observational periods (entire weeks) when the range in hourly average air temperature for the sagebrush site exceeds the minimum and maximum hourly average air temperatures and range in air temperatures at both the montane and subalpine sites.