COS 132-3 - Stability in community productivity in space: Vegetation indicators

Thursday, August 10, 2017: 8:40 AM
E145, Oregon Convention Center
H. Wayne Polley, Grassland, Soil & Water Research Laboratory, USDA, Agricultural Research Service, Temple, TX and Brian J. Wilsey, Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA
Background/Question/Methods

Improving our capability to manage spatially-variable ecosystems is a priority in a rapidly changing world. Management capability could be improved by identifying readily-measurable vegetation properties as surrogates or predictors of management targets. We evaluated two vegetation properties, species diversity and community-weighted values of specific leaf area (SLA), as predictors of inter-annual stability (inverse of variability) of aboveground net primary productivity (ANPP) at local and meta community scales. Meta communities were created by aggregating patches (local scale) of spatially-distinct assemblages of perennial plant species from grassland biodiversity experiments in Texas, USA.

Results/Conclusions

Increasing weighted SLA stabilized ANPP at the largest spatial scale by increasing annual productivity. Conversely, increased variability in SLA stabilized ANPP of grassland patches (local scale) by reducing the influence of precipitation variability on productivity. Increasing species diversity over the narrow range measured destabilized ANPP by reducing mean productivity because stability was high among exotic C4 grasses that dominated productive, low-diversity plots. Our results indicate that community ANPP may be stabilized by both high values of and large inter-annual variability in weighted SLA and, more generally, identify SLA variation as a tool to estimate community stability and contributing mechanisms.