 |
|
 |
 |
||||||||||||||
Vegetation of the Northern Lake States
Pre-settlement Vegetation
Prior to settlement by Europeans in the late 1800's the northern portions of Michigan, Wisconsin, and Minnesota were covered by closed canopy forests of northern hardwoods and conifers interspersed with lakes, wetlands, and rivers. The forest landscape hadn't changed drastically for at least the previous 3000 years (Davis 1981), although local variations in soil and topography, coupled with disturbances by windstorms and fires created a mosaic of different forest types. Detailed reconstructions of the original vegetation have been derived from General Land Office surveys for Wisconsin (Finley 1976) and Minnesota (Marschner 1975), while an older map exists for Michigan (Veatch 1928). According to Frelich (1995), the pre-settlement distribution of forest types in this region consisted of the following major forest types:
|
Forest Type |
% Cover |
| Northern Hardwoods |
47 |
| Swamp Conifer |
13 |
| Red Pine and White Pine |
12 |
| Spruce/Balsam Fir/Paper Birch |
10 |
| Oak-Hickory |
9 |
| River Bottom Hardwoods |
6 |
| Jack Pine |
5 |
Approximately 68% of the 32.7 million hectare forest area consisted of old growth, only 1.1% of which remains today. According to Frelich, about 4.4% of the old growth swamp conifers survived the logging era, along with 0.2% of old growth northern hardwoods, 0.6% red-white pine, 2.6% spruce-fir-birch, 0.02% oak-hickory, 0.2% river bottom forests, and 3.0% jack pine. By far the largest area (approximately 40%) of remnant old growth forest occurs in the Boundary Waters Canoe Area (BWCA) of northeastern Minnesota. Other significant areas of old growth forest exist in the Porcupine Mountains State Park of Upper Michigan, Sylvania Wilderness Area in the Ottawa National Forest, and private lands in the Huron Mountains northwest of Marquette, Michigan.
On July 4th, 1999, a major thunderstorm passed through northeastern Minnesota and blew down or affected approximately 478,000 acres of forest, including 300,000 acres in the BWCA Wilderness. This storm disturbed significant areas of old growth forest and provides an outstanding opportunity to witness the natural processes of ecological succession in this region.
Current Vegetation
Today, the Northern Lake States landscape is still dominated by forests, but their age and composition have been modified extensively by human activities. In particular, early successional stands of aspen and paper birch have replaced much of the vast old growth hardwoods and pines. Northern hardwoods still cover much of northern Wisconsin and Upper Michigan, but most of the forest consists of young or moderately aged trees that are harvested periodically.
Current vegetation maps of the Northern Lake States are now available through interpretation of satellite images. Although age of the forest typically is not depicted on these maps, they provide useful tools for resource management and for assessing the potential distribution of plants and animals. The following links provide current land cover maps for this region:
- Northern Lake States land cover map based on AVHRR satellite images (U.S.F.S.)
- Northern Wisconsin land cover based on Landsat TM Imagery (WISCLAND)
- Wisconsin land use and land cover based on images from National High-Altitude Photography Program (WISCLAND)
- Minnesota land use and cover based on 7 land use data sources (Minnesota DNR)
References
Curtis, J.T. 1959. The Vegetation of Wisconsin. University of Wisconsin Press. Madison.
Davis, M.B. 1981. Quaternary history and the stability of deciduous forests. pp. 132-153 in D.C. West, H.H. Shugart, and D.B. Botkin, eds., Forest Succession: Concepts and Applications. Springer-Verlag, New York.
Finley, R.W. 1976. Vegetation of Wisconsin in the 1830's (map). Cartographic Laboratory. University of Wisconsin-Madison.
Frelich, L.E. 1995. Old forest in the Lake States today and before European settlement. Natural Areas Journal 15:157-167.
Marschner, F.J. 1975. The Original Vegetation of Minnesota (map). U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN.
Veatch. J.O. 1928. Reconstruction of forest cover based on soil maps. Quarterly Bulletin of the Michigan Agriculture Experiment Station 10:116-126.
Biodiversity Topics: Introduction . Plants . Animals . Mammals . Birds . Reptiles & Amphibians . Arthropods . Spiders . Insects
© 2001-2004 The Cofrin Center
for Biodiversity and the University of Wisconsin Green Bay,
All Rights Reserved
Last
updated on
January 12, 2006