The management of natural multiaged longleaf pine (Pinus palustris) communities on national forests of the southeastern United States affects their biological diversity (including but not limited to populations of the endangered red-cockaded woodpecker, Picoides borealis). Because an important element of planning for silvicultural treatments by the Forest Service involves estimations of the future growth potential of existing trees, we used data from the Apalachicola National Forest in northern Florida to develop an appropriate growth equation.  

Results/Conclusions

Our data consist of estimates of the structure of a random sample of mature multiaged stands on the forest and include more detailed measurements from 16 representative stands. Using a linear mixed model, we analyzed patterns of growth derived from increment cores, then estimated growth for a recent interval (1988-1997), on the basis of observed characteristics of component trees and stand structure. We also compared the results directly with the predictions made by the growth equation in the Forest Vegetation Simulator (FVS) used by the Forest Service. The data used to develop the Southeastern Variant of the FVS model were largely derived from even-aged stands, raising questions about its suitability for predicting the development of multiaged stands. We do not yet know the generality of our equation. So far our emphasis has been on the importance of understanding growth dynamics among complex structured stands within a single forest being managed for biodiversity in addition to timber production.