Current and future status of the Fraxinus nigra swamp in the Bessey Creek Nature Preserve, Cheboygan County MI

Abstract

With the continued movement of pests such as the emerald ash borer (Agrilus planipennis), northward into upper Michigan, current vegetation analysis will be important to understanding how different plant communities will be affected. In this study, the woody vegetation of Bessey Creek Nature Preserve (BCNP) was measured and analyzed to provide a more complete knowledge of the tree community of BCNP. We sampled tree species with a diameter at breast height (DBH) of >1.5 cm. Both the east and west sides of Bessey Creek were sampled using a plotless point-quarter method. We recorded ten species, with an Acer rubrum complex and Fraxinus nigra dominating the Preserve with relative densities of 34.5% and 27.3% respectively. We found, however, the most frequently observed trees were not the biggest. Thuja occidentalis and Ulmus Americana, though uncommon, had the highest mean DBH. The mean canopy coverage was 85.93%. This value and the relative density of Fraxinus nigra are expected to fall with the impending spread of the emerald ash borer to this area. The loss of F. nigra will create opportunities for shade intolerant species to grow; reflecting what seems to have happened in the past with the loss of U. americana. We expect that the forest will continue to be dominated by Acer rubrum and its hybrids in the future.