Our primary objective is to provide an improved understanding of the biological and climatic controls over carbon (C) and energy cycles during and after a successional shift from a mature aspen to a young mixed confer/deciduous forest ecosystem that will be widely distributed across the upper Great Lakes region in coming decades. In Spring 2008, we implemented the Forest Accelerated Succession ExperimenT (FASET) by stem girdling all aspen and birch (>6,700 trees, ~35% canopy LAI) within a 39 ha area. A suite of ongoing ecological and meteorological measurements conducted in treatment and control stands before (2007) and after (2008 onwards) the succession treatment are used to quantify effects of climate, species composition, and canopy structure on the forest C cycle.