RAPID Proposal: Modification of the impact of insect disturbance on carbon cycling by fire

University Of Arizona, Tucson AZ

Investigators

Abstract

This RAPID project takes advantage of a wildfire from the summer of 2012 to study the impacts of multiple disturbances on the functioning of pine forests in the Rocky Mountain region. The High Park Fire was the largest and most damaging in Colorado history, although fires of its magnitude are expected to become more common throughout the region in a warmer future. In this case, the range of disturbance histories within the perimeter of the fire area provides a rare opportunity to study the impact of pre-fire disturbance history on forest carbon and nutrient cycling. The investigators will make measurements of the amounts and distribution of remaining living and dead organic matter and chemicals in vegetation, on the ground and in the soil in burned and unburned forest patches, while also noting whether or not the patches had been previously infested by mountain pine beetles. This will enable tests of the additive impacts of insect outbreaks and wildfire and enable more informed predictions about potential forest conditions in the future in this region. Instruments will be installed by university scientists in plots burned in the fire that were also either infested or not by beetles during the most recent outbreak and compared with unburned plots. The U.S. Forest Service will measure trees, ground cover and soil conditions on the ground in the plots that can be resampled and compared to measurements made in the future. New analytical techniques will be applied to characterize soil organic matter composition and age. Finally, a newly available aircraft from the National Ecological Observatory Network equipped with hyperspectral and LIDAR sensors will be flown to provide blanket coverage of immediate post-fire surface conditions in the entire fire area so that results can be extrapolated from plot measurements. This project involves a novel collaboration of multiple universities in Colorado and Arizona, NEON, and the U.S. Forest Service that will provide valuable information to forest managers as they contemplate a future with more fire, as well as unique scientific insights into how history affects the responses of forest ecosystems to multiple stressors.