Landcover is expected to change in the high latitudes in the future due to warming climate, precipitation changes, and rising carbon dioxide content. Past studies have shown that changes in land-cover will be associated with changes in vegetation, primarily tree line migration and shrubification. These changes in vegetation can feedback to climate through the balance of plant carbon uptake due to increased availability of nitrogen and release of carbon to the atmosphere from increased decomposition. In addition to the carbon cycle feedbacks, changes in vegetation can also change the surface energy and water balances through modifications in land surface albedo and evapotranspiration. However there is a lack of studies that attempt to understand how vegetation changes in the future interacts with permafrost degradation and deep soil carbon that can subsequently change the terrestrial carbon balance and surface energy balance in the coming century. In this study, we use a mechanistic ecosystem model (ecosys) to model vegetation dynamics under changing climate at high latitudes, and quantify changes in carbon, water, and energy balance associated with these vegetation changes.