Sedgwick Reserve

23 Feb, 04 AM - 24 Feb, 04 AM

I will be working in the grassland fertilization plots managed by Stan Harpole. I predict that nitrogen addition to a grassland ecosystem would alter the vertical distribution and turnover of soil organic matter (SOM). I am studying this interaction in a California grassland that has been fertilized at 0, 1, 4, and 10 g N m-2 y-1 for 4-6 years. My hypothesis is that as nitrogen availability increases, plants will decrease allocation of photosynthate belowground to roots and mycorrhizae and increase allocation to shoots. Because aboveground NPP results in a carbon input to the soil surface, but belowground NPP is directly added into the soil profile, carbon pools in the litter (O horizon) and surface soil (A horizon) are expected to increase relative to the subsurface soil (B horizon). Furthermore, I expect that reduced allocation to mycorrhizae will result in a shift in the microbial community toward bacteria and saprotrophic fungi.

Visit #12049 @Sedgwick Reserve

Approved

Under Project # 5396 | Research

Soil carbon and microbial dynamics along vertical and nitrogen gradients

graduate_student - University of California, Irvine

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David LeBauer Feb 23 - 24, 2007 (2 days)

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Studio Apartment 1 Feb 23 - 24, 2007