End-point diameter and total length coarse woody debris models for the United States

Abstract

Coarse woody debris (CWD) may be defined as dead and down trees of a certain minimum size that are an important forest ecosystem component (e.g., wildlife habitat, carbon stocks, and fuels). Due to field efficiency concerns, some natural resource inventories only measure the attributes of CWD pieces at their point of intersection with a sampling transect (e.g., transect diameter) although measurements of large-end diameter, small-end diameter, and length are often required by natural resource managers. The goal of this study was to develop a system of empirical models that predict CWD dimensions (e.g., large-end diameter) based on CWD attributes measured at the point of intersection with a sample transect and ancillary data (e.g., ecological province). Results indicated that R-squared ( R 2) values exceeded 0.60 for most of this study's CWD large-end diameter and small-end diameter with only fair results for the length models. The mean residuals of numerous CWD models were within the measurement tolerance expected of actual field crews. Despite remaining unexplained variation, these CWD models may provide foresters with an alternative to the time-consuming activity of measuring all CWD dimensional attributes of interest during large-scale forest inventories.