HYDROLOGIC PROCESSES, SCALE, CLIMATE VARIABILITY, AND WATER RESOURCES FOR SEMIARID WATERSHED MANAGEMENT
Location: Southwest Watershed Research
Title: Integrating est.of ecosystem respiration from eddy covariance towers with automated measures of soil respiration: Exam. the dvlpt. and influence of hysteresis in soil respiratory fluxes along a woody plant gradient 2026
Submitted to: Ecological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2009
Publication Date: August 7, 2009
Citation: Barron-Gafford, G., Scott, R.L., Jennerette, G.D., Huxman, T.E. 2009. Integrating est.of ecosystem respiration from eddy covariance towers with automated measures of soil respiration: Examining the development and influence of hysteresis in soil respiratory fluxes along a woody plant gradient. [abstract]. Ecological Society of America Annual Meeting, Albuquerque, NM, Aug. 2-7,2009.
The physiognomic shift in ecosystem structure from a grassland to a woodland may alter the sensitivity of CO2 exchange to variations in growing-season temperatures and precipitation inputs. One large component of ecosystem flux is the efflux of CO2 from the soil (soil respiration, Rsoil), which is a function of both biotic (vegetation cover type, litter quality, rooting depths) and abiotic (resource availability, temperature) factors. The relative importance of these drivers has not been fully quantified under these transitional states, but doing so is particularly of interest within the semiarid southwest where temperature and available moisture vary and covary throughout a growing season and vegetative cover change is rampant. Determining when ecosystems are temperature sensitive and when they are not is vital for predicting future source/sink status of these ecosystems as they experience woody plant encroachment. Within this study, we used a combination of the traditional soil-collar technique and soil CO2 sensors to obtain an extensive temporal and spatial estimation of Rsoil at each site along with eddy covariance towers to estimate total ecosystem respiration. Measures of Rsoil were made under grasses, shrubs, and in bare spaces so that the individual responses of multiple microhabitats could be analyzed within each site.