D.B.H. and Survival Analysis: A New Methodology for Assessing Forest Inventory Mortality

Abstract

Tree mortality has typically been assessed in Forest Inventory and Analysis (FIA) studies through summaries of mortality by location, species, and causal agents. Although these methods have historically been used for most of FIA's tree mortality analyses, they are inadequate for robust assessment of mortality trends and dynamics. To offer a new method of analyzing tree mortality in forest inventories, we used survival analysis techniques to estimate survival and hazard functions for FIA periodic inventories in Minnesota. The study?s method for applying survival analysis techniques to FIA inventories successfully estimates survivor and hazard models. Classifying trees into classes of d.b.h. and d.b.h. growth may facilitate applying of survival analysis techniques by providing a surrogate for tree ages and vigor. Applying survival analysis techniques to forest inventories allows FIA inventory analysts to test tree mortality hypotheses and summarize regional tree mortality trends, and affords a solid foundation for development of individual tree mortality models.

Parent Publication

• Proceedings of the fourth annual Forest Inventory and Analysis symposium

Citation

Woodall, Christopher W.; Grambsch, Patricia L.; Thomas, William. 2005. D.B.H. and Survival Analysis: A New Methodology for Assessing Forest Inventory Mortality. In: McRoberts, Ronald E.; Reams, Gregory A.; Van Deusen, Paul C.; McWilliams, William H.; Cieszewski, Chris J., eds. Proceedings of the fourth annual forest inventory and analysis symposium; Gen. Tech. Rep. NC-252. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Research Station. 65-69