Linking minirhizotron images to soil physical properties and microbial diversity (TER 2)

The prototype of the automated minirhizotron (AMR) has demonstrated better image quality than conventional manual minirhizotrons. The AMR is capable to record images at user-defined intervals that will be able to capture short-term ecological changes. We have compiled an image database with >60,000 images from manual minirhizotrons at the James Reserve, CA since June 2005. Images were analyzed manually and we used the MARK capture-recapture program to calculate the root survival rate. Preliminarily results suggest that new-born roots have a shorter lifespan than old ones (9 days vs. 24 days). Additionally to the root image analysis we have data from our soil sensor array or soil temperature moisture and soil CO2. We measured CO2 concentration at three soil depths to calculate soil respiration based on CO2 gradients and diffusivity. Data collected from these sensors have increased the understanding of spatio-temporal variation in soil respiration and its relation with root dynamics. To identify the fungal biota participating in soil biogeochemical processes we isolated fungal hyphae from soil