Southern Sierra Critical Zone Observatory

The rain-snow transition zone is particularly vulnerable to large & rapid changes in climate & landcover. While this zone undergoes rapid seasonal changes, going from snowcoverto wet soil to dry soil over a 1-2 month period, climate warming will shift this transition period earlier or eliminate it entirely. The result will be major changes in seasonal-to-interannualcritical zone processes involving water, nutrients and ecosystem response of the largely mixed conifer forest found in the rain-snow transition zone. Forest density & the threat of catastrophic fire in the zone are very high, leading to the further likelihood of changes in longer-term critical zone processes. Steep gradients in precipitation patterns, along both elevation and aspect, plus rapid seasonal changes, make this zone an excellent natural laboratory for studying how critical zone processes respond to perturbations, & particularlyhow the water cycle drives critical zone processes. Also, the characteristic spatial differences along gradients offer the opportunity to substitute space for time. Award Abstract #0725097 http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0725097 Southern Sierra Critical Zone Observatory - https://snri.ucmerced.edu/CZO Digital Library: Sierra Nevad San Joaquin Hydrologic Observatory - https://eng.ucmerced.edu/snsjho