A comparison of species composition, size structure and susceptibility to invasion of logged and unlogged landscapes in Cheboygan County, Michigan.

Abstract

Human-induced disturbances, such as logging, have significantly altered ecosystems by removing nutrients and biomass. Between 1840 and 1900, the forest ecosystem at Grapevine Point on Douglas Lake in Cheboygan County, Michigan, was selectively logged for pines, hemlocks and northern hardwoods. One forest ecosystem at Colonial Point on Burt Lake in the same county escaped logging. This study compared species composition, species richness, relative abundance of species, size structure, density, and presence of invasive species between the logged community at Grapevine Point and the unlogged community at Colonial Point. I found that species composition did not vary greatly in the overstory (plants with >= 3 cm dbh) or the understory (plants with diameter < 3 cm at 50 cm but taller than 50 cm), but that ground cover (plants less than 50 cm tall) of the unlogged site was much more diverse. Acer saccharum dominated all three layers at both sites. The overall size structure and density of the sites did not differ significantly. I only found two individuals of one invasive speces at the logged site. Overall, the study showed that the forest ecosystems at the sites are not vastly different. However, the study does not support the indication that logging does not change the plant community structure of forest ecosystems.