Foresters and scientists have developed several methods for classifying woodlands. These classifications help describe tree species that are currently present, or the combination of vegetation that would naturally occur on the site if it were undisturbed for a long period of time, or the site quality for growing particular tree species.
The "forest type" classification is based on the predominant tree species over an area of woodland. Forest types are named for one to three tree species that comprise at least 20 percent of the basal area in a mature stand or a predominance of stems in seedling and sapling stands. Forest type classification has been standardized across the United States, but each forest type has many variants. A forest type designation recognizes the combination of tree species currently in a woodland, but that type may not be the best type to grow on the site where it exists. We use forest types in this book because they are relatively easy for landowners and foresters to recognize and you do need to base management decisions on what tree species are present, even if you're trying to move the stand toward another combination of tree species that is better suited to the site.
A "plant community" classification considers site factors in designating the trees and other plants most likely to occupy a site if it were undisturbed for a long period of time.
A "vegetative habitat type" (also known as "site type" or "native plant community") classification identifies forest sites along a soil moisture-nutrient gradient. It takes into consideration soil texture, fertility, and moisture and leads to designation of tree species best suited to each site type. Site types are recognized by characteristic understory plants rather than tree species.
An "gecological classification" system is based on climate, geology, landforms, landscape position, soil and vegetation. This hierarchical system first defines large large-scale ecosystems that are multistate in scope (a province), then subdivides those ecosystems into smaller and smaller parts, down to a few acres (ecological land type phase) as the criteria are refined.
This chapter describes management of important forest types in the Lake States–Minnesota, Wisconsin, and Michigan. These descriptions are brief and may not provide adequate information for managing specific stands because so many site types and species combinations exist. A forester should inspect your woodland and prepare stand management plans before you implement any forestry practices.
Range maps help you determine what tree species are likely to be found in your area. A species usually grows better and its wood has greater commercial potential in the heart of its range, as opposed to the edge of its range where environmental factors may limit its growth.
Site index curves help you determine whether the growth potential on your land is high or low for a species. To determine the site index for a species on a particular site, you need to know the average age and total tree height for trees of that species on the site, then refer to site index curves such as those found in the appendixes of this book.