Angelo Coast Range Reserve

28 May, 09 AM - 31 May, 03 AM

Though soil fungi commonly represent the largest fraction of microbial biomass in soil, only a small proportion (~3%) of soil fungi have been identified and even fewer have been functionally characterized. Given that we know the soil fungal community plays a key role in the transfer of carbon from plants to soil and the recycling of soil carbon and nutrients, it is important to understand this community and how it responds to environmental change. This proposal will investigate the effects of predicted future shifts in precipitation patterns on soil fungi and their function in a California grassland system. Though climate models agree that precipitation will increase in northern California, they disagree on whether the additional precipitation will fall within the boundaries of the present winter rainy season or will occur later in the spring and thus extend the rainy season. In a northern California grassland, rainfall addition plots were set up in 2000 to receive either more intense winter rain or an extended rainy season. Control plots received no additional rain. The proposed study will use these plots to address the following questions: 1. How are soil fungal communities compositionally and functionally affected by altered precipitation regimes? 2. How are soil carbon pools mediated by fungi affected by altered precipitation regimes? 3. What fungal species and functional changes are responsible for changes in carbon cycling under the different rainfall treatments? Twice a year (early season, late season) for two years, soils and plants will be collected from the treatment and control plots to identify changes in fungal-mediated carbon pools, including hyphal networks, root colonization, chitin, ergosterol, glomalin, total microbial carbon, and total soil carbon. Fungi in soils and roots will be identified with DNA-based methods and culturing will be used to characterize functional aspects of fungal growth. Changes to decomposition rates will be examined in the second year with a 13C-labeled litter bag experiment. Fungal function in carbon transformations will be examined in the second year using stable isotope probing of both fungal RNA in roots and soils from the decomposition experiment (fungal role in the fate of plant litter carbon) and from a second experiment with plants exposed to 13CO2 in the field (fungal role in the fate of carbon from root exudates). The combination of molecular, culturing, and stable isotope techniques, allows this study to link pattern and mechanism to increase our understanding of how fungi are affected by potential future precipitation scenarios, and what the role of soil fungi in carbon cycling becomes in those scenarios.

Visit #10170 @Angelo Coast Range Reserve

Approved

Under Project # 6834 | Research

Precipitation&SoilFungi

faculty - University of Texas

Reservation Members(s)

Christine Hawkes May 28 - 31, 2006 (4 days)

Reserve Resources(s) | Create Invoice

Wilderness Lodge 1 May 28 - 31, 2006