Habitat Relationships of Avian and Bat Species Assemblages within Managed Pine Forests of the Great Lakes

Abstract

Intensive forest management, resulting in plantations, has been criticized for potential reductions in biological diversity when compared to natural forests. Commercial forestry is an important contributor to the economy of the Great Lakes states, resulting in increased management intensity and frequency within forest landscapes. Private landowners are experiencing increasing demands to manage for ecological objectives, placing more value on biological diversity. However, landowners currently have little information to aid development of practical management plans that integrate ecological and timber management objectives. In the Great Lakes Region, red pine (Pinus resinosa) is being restored to its pre-settlement range and jack pine (Pinus banksiana) is being replaced with more economically valuable species. As red pine increases in the great lakes, jack pine stands will become increasingly rare. Therefore, understanding the relative contributions of each forest type is critical for maintaining wildlife diversity in managed forests. I present results of a study evaluating habitat relationships of avian and bat communities within managed pine forests of Minnesota and Wisconsin, including the relative contributions of red pine and jack pine forest types. In 2008 and 2009, I conducted avian point count and acoustic bat detection surveys in 12 red pine and 12 jack pine stands. I measured stand- and macro-level habitat attributes, and present multiple stepwise logistic and liner regression modeling results that relate presence and abundance (birds) or activity (bats) with habitat attributes. Over the course of this study, 60 avian species were detected in jack pine, and 48 in red pine. In red pine and jack pine, 5 species of bats were detected. My results were as expected avian presence and abundance and bat presence and activity varied with forest structure. Mann-Whitney U-tests identified significant differences in habitat structure, avian species abundance and bat activity between red and jack pine, with jack pine having greater below canopy structure and avian abundance and diversity and bat activity. The identification of habitat variables associated with greater avian and bat diversity within managed forests could provide needed information to land owners for enhancing the wildlife habitat potential of their lands. The importance of a commercial aged jack pine component in the landscape could also improve forest management and conserve wildlife diversity.