Fuel reduction treatments and their ecological impacts on native bees

As a result of decades of wildfire suppression policies, forests across the U.S. were left overgrown. With this excess fuel came increased wildfire risk. In the Uinta Mountains of Utah, the USFS is in the midst of a multi-year project which employs thinning and pile burning to remove potential fuel while promoting the health of the forest. Felled trees are placed in slash piles to later be burned. Determining whether cavity-nesting bees are nesting in slash piles is a primary focus of this project. To get an idea of what species are present, we conducted sampling via hand netting and trap nests which were left out for the duration of the season. During season one, we collected woody material from piles which was brought back to the lab and placed in screened enclosures to monitor for emergence. For season two, instead of collecting wood, we erected screened enclosures over piles and fit them with traps to passively collect insects throughout the season. While a broad goal of this project is to assess how various forest treatments are impacting native bees, we have a particular interest in the potential for slash piles to be functioning as a nesting resource for cavity- and ground-nesting bees. The aim of this project is to provide land managers with information so that they may implement informed management directives which will maximize benefits to the plant and pollinator communities while simultaneously accomplishing their goal of reducing fuel load on the landscape.