COS 84-4 - CANCELLED - What's happening to our big trees?

Abstract: Mortality among the world's largest trees is an issue of conservation concern. However, putting mortality numbers into context can be difficult. Are recent die-offs abnormal, or simply part of the natural cycle of tree death and regeneration? Is big tree mortality outpacing big tree recruitment? To address this, we used Forest Inventory and Analysis (FIA) data, collected by the US Forest Service, to estimate the flux of large tree populations across the western United States. This dataset allows us to determine the mortality rate of our largest trees, in addition to the recruitment rate. Our analysis reveals that on the whole, large tree populations in the western US have increased during the past decade. The population of large Douglas firs has increased faster than any other species. However, certain species have seen significant decreases in their big tree populations, including sugar pine, subalpine fir, and Engelmann spruce.