Issue At Hand

Contemporary harvesting practices frequently result in simplification of structure and composition in managed forest stands in comparison to their natural counterparts. Loss of heterogeneity within stands may pose a problem for maintaining of biodiversity in perpetuity.

Although it is known that birds respond to heterogeneity, it is unclear 1) what elements of heterogeneity are generally important and 2) whether some harvesting scenarios can provide more beneficial habitat than others.

What We Hope to Accomplish

Modified Transect Survey Design

How We Go About It

During the winter of 2003, experimental treatments sites were created in red pine forest to simulate partial harvesting practices; other sites served as a control.

Three times during the summers of 2003, 2005, and 2007, each experimental treatment was surveyed for birds. All individuals seen or heard while walking survey transects were recorded spatially within the effective sampling area.

What We Are Finding

Ovenbirds, Least Flycatchers, Red-eyed Vireos, Pine Warblers, Chestnut-sided Warblers, Chipping Sparrows, and American Redstarts are the most common birds overall.

Bird community composition did not differ between treatments in 2003, but did in 2005, with Dispersed Retention, Small Gap, and Large Gap treatments experience higher avian richness, diversity, and abundance than the Controls. As of 2005, we detected no difference between different overstory or understory treatments.