The human-built environment disrupts ecological processes that mitigate pest outbreaks in natural settings. We will explore how and why pests reach outbreak levels in urban forests. The effects of limited biodiversity, replacement of native species with aliens, warming of cities due to impervious surfaces and climate change, and disruptive effects of inputs such as pesticides and fertilizers will be discussed. We will review steps that can be taken to ameliorate or reverse these disruptive factors.

Mike Raupp is a professor at the University of Maryland. His programs focus on invasive species, urbanization, and climate change and his outreach provides training on IPM to arborists, master gardeners, and the general public. He has received a dozen regional and national awards including the Secretary of Agriculture’s Award for Environmental Protection, the Entomological Society’s Achievement Award in Extension, and the Richard Harris Authors Citation from the International Society of Arboriculture.