Director, Center for Tree Science; The Morton Arboretum

The Consequences of Burn Pile Scars for Midwest Oak Ecosystem Biodiversity

To restore oak savannas in the Midwestern US, ecosystem stewards and managers cut invasive brush and thin trees, creating woody debris brush piles. Brush pile burning is the top strategy for dealing with this debris. Though individual piles are generally small (2-5 m in diameter), burning them can produce extreme soil temperatures that adversely affect soil processes and biota beneath the piles. Brush piles are often produced at high density in small management units undergoing ecological restoration, which may have consequences for ecosystem functioning and regional biodiversity conservation. With approximately 5,000 brush piles being built and burned annually in the Chicago region, there are concerns from the ecological restoration community about the effect of burn scars on regional biodiversity and interest in developing strategies for minimizing these impacts. However, the ecological effects of these burn scars, which may include long-term changes in plant and fungal communities and soil biogeochemistry, are virtually unexamined. To meet the needs of the restoration community and improve our ecological understanding of burn scar successional dynamics, we established a series of studies to 1) characterize short- and long-term effects of brush pile burns on plant and soil biodiversity; 2) identify the management choices that minimize or maximize these effects; and 3) evaluate post-burn strategies for mitigating brush pile burning effects on biodiversity. In this talk, I will discuss current findings from a large-scale survey, a chonosequence study, and a restoration treatment experiment.