Soil Carbon is Root Carbon, but Moisture is Key

Presenter: Katherine Heckman

Rooted in Research Webinar Series:Understanding What’s Underground - A Belowground Ecology Webinar Mini-Series

There is growing evidence that changes in moisture may be more important than changes in temperature where forest soil carbon is concerned. Water is needed not only for root production and sustainment, but moisture in excess of root demand is needed to facilitate decomposer access to substrate, to weather minerals, to provide movement of dissolved components through the mineral matrix to allow for interaction between mineral surfaces, microbes and growth substrate. Where water is more abundant, connections between inputs and the size and turnover of soil organic matter pools can be identified and explored. However, in systems where moisture is limited, the lack of sustained interaction of microbial communities, substrate and mineral surfaces creates disconnects between inputs and their transformation and degradation, leading to a disconnect between metrics of soil organic matter abundance and persistence.