Midwest Fish & Wildlife Conference 2018

AUTHORS. Annie Hawkinson, Rebecca Montgomery, Lee Frelich - University of Minnesota; Charlotte Roy, Lindsey Shartell - Minnesota Department of Natural Resources

ABSTRACT. Lowland brushlands in Minnesota are disturbance-dependent ecosystems that provide habitat for 80 wildlife species on the MN DNR Species in Greatest Conservation Need (SGCN) list, nearly half of which are birds. Historically, burns occurred during spring, summer, and fall months, resulting in a characteristic patchy landscape. Current management in East-central Minnesota is limited to mowing and spring prescribed burns; shorter burn windows complicate summer and fall fires but burning during these seasons could benefit different species. In other habitats, burn season impacts plant growth rates, vegetation structure, and composition, factors critical for avian breeding habitat. However, both the vegetation and avian community are poorly studied in brushland regardless of burn regime. This three year study in East-central MN considers the role of season in effectiveness of prescribed burns to meet management objectives. Prior to and following burns we surveyed breeding birds (point counts) and vegetation (fixed radius plots). Here we compare point count data before and after burns. Patterns suggest that the diversity and number of avian species and individuals in lowland brush habitats increase after burns; however current low sample size means we have low power to detect significance. Species diversity increased significantly after spring burns. For 10 out of 11 common species, we recorded more detections after burns. For seven of those, detections decreased where burns had not occurred. Most increases occurred in spring burn sections, but different responses to the fall burn suggest management would require a diverse burn regime to maximize biodiversity. It is important to note that the fall burn sample size was half that of control and spring. Two summer burns were recently completed and we hope additional fall and spring burn attempts will be successful. After we complete final post-treatment surveys, we will provide recommendations to lowland brushland managers on prescribed burn regimes.