Incorporating Mountain Pine Beetle Impacts on Stand Dynamics in Stand and Landscape Models: A Problem Analysis

Abstract

Due to numerous operational, legal and ecological constraints, a large portion of the millions of ha of lodgepole pine affected by the current mountain pine beetle outbreak will not be salvage logged. Understanding how unsalvaged stands and landscapes will develop is critical for assessing the socio-economic and ecological impacts of the outbreak. Most modelling work in British Columbia has been of mountain pine beetle population development, outbreak spread, and interaction with management treatments. Further work is needed to project impacts on stand and forest development. Data obtained from our companion study have some implications for stand modelling. In the Chilcotin outbreak, surviving trees in all diameter classes continued to grow well during the course of the outbreak. Many more small diameter trees are killed in an outbreak than mountain pine beetle population models predict. There was extensive mortality due to Ips spp. after the collapse of the mountain pine beetle outbreak. Surviving pine and non-host species responded well to release from overstory competition. This project will identify pathways to include mountain pine beetle impacts in stand and forest growth models focussing primarily on PrognosisBC and its extensions, the Fuels and Fire Effects Model, and the Westwide Pine Beetle Model.