Southern Sierra Critical Zone Observatory: a Hub for Multi- and Interdisciplinary Research on Soil Development, Forest Water Use, and Biogeochemistry in the Sierra Nevada, California
Abstract
The NSF-funded Southern Sierra Critical Zone Observatory (SSCZO) pursues questions on the evolution of the Critical Zone; regolith-biota influence on the water cycle, ecosystems, and biogeochemical fluxes; and implications of Critical Zone function for ecosystem services. SSCZO was established in 2007 at Providence Creek, co-located with the Kings River Experimental Watersheds (USDA Forest Service). SSCZO now includes four field areas at elevations from 400-2700 m on the western slope of the Sierra Nevada, California. Elevation creates large variation in temperature and precipitation in this Mediterranean climate. Rain dominates at lower elevations, and snow increases with increasing elevation. Biomes transition from oak/pine-savannah to mixed conifer and subalpine forests. Permanent installations include four gas eddy flux towers, and instrument clusters measuring snow, air temperature, and soil moisture and soil temperature. Short-term investigations have researched soils, regolith, and vegetation, through sampling, geophysics, and deep-push drilling, among other projects.
In the past 12 years, SSCZO has made several major findings. Analysis of the 2012-2015 California drought showed that high temperatures, dense vegetation, and increased evapotranspiration compounded year-over-year drawdown of subsurface water stores; these factors were major contributors to high mortality in this part of the Sierra Nevada. In addition, increased water use by vegetation decreases contributions to streamflow, with implications for the entire state. SSCZO has also found that regolith thickness is coupled with net primary productivity; NPP is highest at mid-elevations, where we also find the deepest regolith, and highest carbon and phosphorus stocks. Deep weathering provides potential water storage, and plant-accessible soil water helps sustain forest health through dry summers. Factors affecting the Critical Zone are expected to change in the future with anticipated warming and uncertain precipitation changes. We work with local and state-level organizers, legislators, and management agencies to contribute to informed decision-making. We welcome researchers who wish to collaborate with us or use our data to inform their own research. More information at criticalzone.org/sierra.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPA13B1021B
- Keywords:
-
- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 1848 Monitoring networks;
- HYDROLOGY;
- 6329 Project evaluation;
- POLICY SCIENCES & PUBLIC ISSUES;
- 6610 Funding;
- PUBLIC ISSUES