Host-tree Geometric Models for Use in Southern Pine Beetle 1 Population Studies 2

Abstract

Regression equations for predicting diameter outside bark (DOB_x) and bark thickness (BT_x) as functions of height and diameter or bark thickness class were developed from data collected as part of a Dendroctonus frontalis population dynamics study. The 2 equations were combined and integrated over height to provide estimates of the phloem area and bark volume infested by the insect. A graphic analysis using the BT_x model showed that eggs/cm³ of bark increase with height, indicating that factors other than BT_x control the egg density per unit area. An example is presented showing the use of the phloem area model to estimate the total number of insects inhabiting a tree.