Modeling endemic bark beetle populations in southwestern ponderosa pine forests

Most bark beetle studies focus on outbreak conditions due to their economic and ecological impacts. However, bark beetle populations are often characterized by rapid shifts between epidemic and endemic phases. Little is known about the ecology of endemic, low density populations due to the difficulties associated with studying them. In this project our goal is to understand how endemic phase bark beetles (Dendroctonus spp.) perceive and utilize their hosts in southwestern ponderosa pine forests. Since weakened trees are essential for the persistence of endemic populations, aerial imagery of the forest was used to map the spatial distribution of individual hosts. Using these maps and 15 years of novel field data, we estimated the size of the region’s endemic bark beetle population. Our results are discussed in the context of host utilization, the long term persistence of bark beetle populations, and the environmental triggers that drive outbreaks.