In forested watersheds, trees are center stage in the carbon cycle. However, tree-based photosynthetic carbon fixation is modulated by interactions with the subsurface microbial biosphere. Previous studies focused on the root rhizosphere, but recent work at the Eel River Critical Zone Observatory (CZO) in Northern California suggests much of the carbon, water and nutrient exchange can occur below the soil mantle in the vadose zone (unsaturated zone) that extends into the underlying weathered bedrock. The product of this work will be new understanding of microbial metabolic potential and activity throughout the deep vadose zone in the weathered bedrock on a highly instrumented and extensively studied hillslope.
Proposer’s Name: Jill Banfield, University of California, Berkeley