In stands of trees with individual grid cell sizes larger than the height of the tallest tree, litterfall occurs within the grid cell. There is sufficient information available on tree growth and forest floor dynamics from the Bonanza Creek LTER site to evaluate the model behavior for soil temperature, moisture dynamics, carbon and nitrogen turnover, and tree growth across both upland and floodplain successional sequences. Currently a number of data sets are available for the state of Alaska. A 90 m DEM derived from USGS data sources is available. This data set can be used to derive relevant elevation, slope and aspect groupings.
Work is close to completion on assembling all current vegetation data bases for the state.
The level IV groupings will also give us the best approach for defining the four primary components of the carbon stores on the landscape. The nitrogen productivity concept represents one approach for developlment of an algorithms for expansion from individual tree to stand or landscape levels of estimation of primary production. Relationship between nitrogen productivity and foliage biomass for aspen, birch, balsam poplar and white spruce stands and individual trees in interior Alaska. The model was able to acurately predict the growth of white spruce and birch trees in an old-growth white spruce forest on the floodplain in interior Alaska. Measured diameter growth for white spruce between 1989 and 1993 averaged 0.9 cm at breast heaight.