Making sense of site index estimates in British Columbia: A quick look at the big picture

Abstract

Site index remains the primary estimate of forest site productivity used throughout British Columbia and around the world. Forest managers often need a better understanding of how various site index estimates are derived in order to effectively apply them in operational settings. Historically, most site index estimates in Canada were derived from the photo-interpreted estimates of stand height and age found in extensive inventories. However, a wider range of data sources and site index tools now make both direct and indirect estimation of site index possible. Consequently, several different site index estimates may exist for any given hectare. The most prominent example involves comparisons of site index estimates derived from natural stand (old-growth) inventories versus the higher estimates frequently observed in post-harvest second-growth stands. These differences can have positive implications for timber supply. An understanding of site tree selection is essential when choosing the best available site index estimate for a given application.