MSA - Ecology/Pathology
Rocca, Jennifer D. , Hawkes, Christine V. .
Fungal community composition and function are directly influenced by altered timing of precipitation.
Soil fungi are prominent players in terrestrial ecosystem functioning, particularly decomposition (saprophytic fungi) and the transfer of carbon and nutrients between plants and soils (mycorrhizal fungi). Both of these processes can be affected by available soil moisture, which is predicted to change with future climate. The majority of climate change models predict more variable rainfall with greater spans of drought However, in ecosystems with Mediterranean climates such as northern California, the timing of altered precipitation is likely to be as important as the magnitude. To test the impacts of proposed climate change, we manipulated rainfall in grasslands at the UC Angelo using rain additions to reflect the HadCM2 and CCM1 climate models. Plots received either additional rain during the current winter rainy season (winter), additional rain in spring as an extension of the rainy season (spring), or no rain addition (ambient). We collected soils during over five years in winter and spring. We used a DNA-based approach to characterize soil fungi, using a combination of cloning, sequencing, and terminal restriction fragment length polymorphism. We also measured fungal abundance in soils and rates of decomposition. We found that both composition and function shifted with both rain treatments and annual differences in ambient rainfall. Spring rain additions that extended the rainy season had the greatest impact, with an increase in hyphal abundance as well as shifts in the overall fungal community. The patterns of change we observed are consistent with a direct response of fungi to altered rainfall, which may ultimately feedback to both the plant community and ecosystem functioning.
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1 - University of Texas at Austin, Integrative Biology, 1 University Station C0930, Austin, TX, 78712, United States of America
Presentation Type: Oral Paper:Papers for Topics
Location: Cottonwood B/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 4:00 PM