Relationships between forest fine and coarse woody debris carbon stocks across latitudinal gradients in the United States as an indicator of climate change effects

Coarse and fine woody materials (CWD and FWD) are substantial forest ecosystem carbon (C) stocks. There is a lack of understanding how these detritus C stocks may respond to climate change. This study used a nation-wide inventory of CWD and FWD in the United States to examine how these C stocks vary by latitude. Results indicate that the highest CWD and FWD C stocks are found in forests with the highest latitude, while conversely the lowest C stocks are found in the most southerly forests. CWD and FWD respond differently to changes in latitude with CWD C stocks decreasing more rapidly as latitude decreased. If latitude can be broadly assumed to indicate temperature and potential rate of detrital decay, it may be postulated that CWD C stocks may be at the highest risk of becoming a net C source if temperatures increase. The latitude at which CWD and FWD C stocks roughly equal each other (equilibrium point) may serve as an indicator of changes in C stock equilibrium under a global warming scenario. Given the complex relationships between detrital C stocks, biomass production/decay, and climatic variables, further research is suggested to refine this studyʹs indicator.