Changes in the source/sink relationships of the Alaskan Boreal Forest as a result of climatic warming

A modified version of the LINKAGES ecosystem simulation model is used to access the changes in the role of forests in the interior of Alaska to act as a source or sink of carbon over a fifty-year period. The study area is the Tanana Valley State Forest (TVSF). The TVSF occupies an area of 5,523 hectares along the Tanana River from the Canadian Border to the confluence of the Tanana River and the Yukon River. The current inventory for the TVSF is used to develop a starting state for the model for ten vegetation classes. The model is run with the current climate until the current stand age for the various vegetation types is reached. Then a 5C increase in mean annual temperature and a doubling in precipitation distributed evenly over the year is gradually added to the model. The model was then used to develop an average estimate of the atmospheric carbon sequestering for the current vegetation distribution of the productive forest types in the TVSF. This value was estimated as 392 g m-2 yr-1 for a 490,000-hectare area of interior Alaska