Climate, soil organic layer, and nitrogen jointly drive forest development after fire in the North American boreal zone

A. T. Trugman, N. J. Fenton, Y. Bergeron, X. Xu, L. R. Welp, D. Medvigy
2016 Journal of Advances in Modeling Earth Systems  
Previous empirical work has shown that feedbacks between fire severity, soil organic layer thickness, tree recruitment, and forest growth are important factors controlling carbon accumulation after fire disturbance. However, current boreal forest models inadequately simulate this feedback. We address this deficiency by updating the ED2 model to include a dynamic feedback between soil organic layer thickness, tree recruitment, and forest growth. The model is validated against observations
more » ... observations spanning monthly to centennial time scales and ranging from Alaska to Quebec. We then quantify differences in forest development after fire disturbance resulting from changes in soil organic layer accumulation, temperature, nitrogen availability, and atmospheric CO 2 . First, we find that ED2 accurately reproduces observations when a dynamic soil organic layer is included. Second, simulations indicate that the presence of a thick soil organic layer after a mild fire disturbance decreases decomposition and productivity. The combination of the biological and physical effects increases or decreases total ecosystem carbon depending on local conditions.
doi:10.1002/2015ms000576 fatcat:x2uokpxymvamhg3z6dkg4hsbj4