D3041: Balsam woolly adelgid: the effects of forest stand characteristics on Adelges piceae susceptibility and damage

Adelges piceae (Ratzeburg), balsam woolly adelgid (BWA) is an invasive forest pest that attacks and kills true firs (Abies sp.) in North America. Die-off in fir populations can contribute to ecosystem decline through a variety of factors including increased erosion, loss of forage and habitat for wildlife, and declines in watershed quality and forest resilience. Due to the high degree of damage and mortality that subalpine fir, Abies lasiocarpa (Hook.) Nutt., has exhibited in response to BWA infestations in the Intermountain West, Utah State University researchers seek to better understand how specific characteristics of fir stands contribute to susceptibility to BWA infestations and intra-stand spread. Over 40 sites have been identified through an interagency effort across northern and central Utah and southern Idaho where BWA or associated damage is present. These stands will be visited for the collection of forest assessment data (species composition, tree size, tree health, etc.) as well as the observation of metrics specific to describing the impact of BWA on individual fir (crown flagging and dieback, gouting, bole infestations). Stand characteristics that heavily contribute to susceptibility, spread, and damage will be identified and quantified. These data will form the basis of a rating system that stakeholders can use to assess the risk of BWA in their stands. Additionally, individual variables included in the rating system may be used to identify areas of concern within stands (such as structure or average size) and guide preventative or responsive treatments to balsam woolly adelgid.