| Climate change impacts on grassland structure and function |
Effects of recent climate change on plants and animals are evident in geographic and elevational shifts in species ranges, altered timing of phenological events, and even the disappearance of some species. How will species, communities, and biomes respond to the more substantial changes still expected? Answering this critical question will require improved understanding of the relative importance of direct climatic effects on species versus indirect effects mediated by changing interactions with resources, competitors, pathogens, and predators. By manipulating climate over whole communities of interacting organisms and measuring responses across several trophic levels above and below ground, we are working toward this improved understanding for grassland ecosystems in California. The Experiment
In 2001, Blake Suttle, Meredith Thomsen, and Mary Power began a large-scale manipulation of rainfall in a grassland at the Angelo Coast Range Reserve in northern California. They developed the experiment to explore potential consequences of future climate change for grassland food webs and for native grassland plants threatened in California grasslands. For the past seven years, thirty-six large plots have been subjected to one of three watering treatments designed to target predictions for the region generated by global climate models. The watering treatments include Watered plots receive 14 to 16 mm of supplementary water every third day over ambient throughout the winter or spring, simulating either an intensification or an extension of California's winter rainy season. Since the experiment began, the research team has grown to include scientists interested in microbial community composition and function, nutrient cycling, mineral weathering, and soil organic matter transformation and storage. Researchers University of California, Berkeley Jillian F. Banfield [web] University of Wisconsin, La-Crosse Meredith Thomsen [web] University of TEXAS at Austin Christine Hawkes [web] Publications Suttle, K.B., M. Thomsen, & M. Power. 2007. Species interactions reverse grassland responses to changing climate. Science 315:640 - 642. (Science Perspectives, 315: 606-7)[link] Rosling, A., K.B. Suttle, E. Johansson, P.A.W. van Hees, & J.F. Banfield. 2007. Phosphorous availability influences the dissolution of apatite by soil fungi. Geobiology. doi:10.1111/j.1472-4669.2007.00107.x (link) Thomsen, M., C. D.Antonio, K.B. Suttle, and W.P. Sousa. 2006. Ecological resistance, seed density, and their interactions determine patterns of invasion in a California coastal grassland. Ecology Letters 9:160-170.[link] Presentations Cruz, K, K.B. Suttle, A.A. Berhe, & J.F. Banfield. 2007. Rainfall variation impact on above- and below-ground biota and soil biogeochemistry in the Eel river watershed. (NCED site visit poster)[link] Press Coverage Long-term Study at Angelo Reserve Produces Surprising Results. University of California, Office of the President [link] Species drop in wetter grasslands. Conservation Magazine. Society of Conservation Biology. [link]
|
.jpg)
