1. Carbon and water cycling along the western Sierra gradient Anne Kelly SSCZO annual meeting August 21, 2012

2. Overview How does climate control carbon and water cycling? How do drought and cold limit growth and water use? Are there thresholds and resiliencies in ecosystem response along a gradient of drought and temperature? Four towers: 400, 1200, 2000, 2800 m – Weather, CO2 exchange, ET – Hourly to interannual – Severely drought limited to severely cold limited with a happy zone in between Dendrometers, sap flux to for individual tree carbon and water cycling Litter collection, soil moisture, soil respiration, etc.

3. P301 – not limited by cold or drought temp PAR VPD soil VWC GEE (tC/ha) NEE ET (mm) tree biomass

4. Seasonality of water and carbon exchange

5. Elevation patterns

6. Future work How does cold and drought control ecosystem type, function, productivity, ET, and phenology along the gradient – Step changes/vulnerability – No changes/resilience How does species’ growth and water use vary along the gradient within species and among species? How do these forests compare to similar forests in Southern California (latitudinal gradient)?