Building the Forest Inventory and Analysis Tree-Ring Data Set

The Interior West Forest Inventory and Analysis (IW-FIA) program measures forestland conditions at great extent with relatively high spatial resolution, including the collection of tree-ring data. We describe the development of an unprecedented spatial tree-ring data set for the IW-FIA that enhances the baseline plot data by incorporating ring-width increment measured from increment cores collected on IW-FIA plots. Whereas the IW-FIA program has used increment cores consistent with traditional forestry (stand age, site index, and vigor), there are key differences in sampling approaches between foresters and dendrochronologists. We describe a framework for preparation, interpretation, and archiving of the IW-FIA tree rings. Early results suggest that the data produced by this framework are useful for growth-and-yield studies, stand dynamics, and dendroclimatology. We discuss the potential for tree-ring data to become a standard component of the FIA program. We also compare and contrast the applications and procedures of dendrochronology with the FIA approach and show how the two sources of data complement one another.