Michigan was, for the most part, forested prior to European settlement.  The map below shows major vegetation assemblages for North America, and illustrates that Michigan's forests were primarily of the "mixed" type---that is, part broadleaf trees and part conifers.

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Source:  Unknown

Actually, when examined on a finer scale, Michigan's forests can be divided into two major groupings: the deciduous forests (oaks, hickories, maples, beech) to the south, and mixed forests (pines, spruces, firs, beech, maples, oaks, aspen) to the north.  The map below shows the general location of the boundary between these two forest provinces--called the floristic "tension zone".


Climate effects on forest patterns
Certain patterns in the present composition of forests in the Lower Peninsula appear to be responses to climatic gradients that extend both south to north and east to west across the state. Moving south to north through the Lower Peninsula, one notices an increase in the number of evergreen (conifer) species. These species (white spruce, balsam fir, jack pine) are boreal in distribution but extend south into northern Michigan on upland sites where they are usually only minor associates of other native hardwoods (though jack pine occurs extensively on sandy uplands). Apparently sensitive to warm, dry summers and neutral or basic soils, and unable to compete with more temperate-climate associates, they are limited primarily to the northern Lower Peninsula--north of a line from Bay City to Muskegon (the tension zone)--and to the Upper Peninsula, where cooler summers and lower evaporation are typical, along with the acidic, sandy soils on which these trees are most competitive. Warmer summer weather with higher evaporation rates seem to restrict their occurrence in southern Michigan.

Soil and topography effects on forest patterns
Probably no environmental factors account for more differences in forest composition than do soil texture and topographic position. Both of these factors strongly influence what amount of annual precipitation will actually be available for plant growth on a given site and thus put limits on which plants will be competitive there. Coarse, sandy soils are porous, have a low water-holding capacity, are often acidic, and usually support trees such as oaks and hickories--or in northern Michigan, jack and red pine with a shrub layer of blueberries. Soils of intermediate texture (loams) usually support a wide variety of species, but shade-tolerant hardwoods such as beech and sugar maple often dominate these sites. In the northern Lower Peninsula, hemlock and yellow birch may prevail along with beech and maple, and in the western Upper Peninsula, where there are no beeches, red oak and basswood are important also. Heavy, clay-rich soils with poor internal drainage may support communities of red or silver maple, ash, elm, and red oak.
    The complex glacial history of the state left a jumbled array of sediments that became soil, and since the soil influenced the composition of both the primeval and present forests, much of the patchwork of local forest patterns can be traced directly back to the state’s glacial heritage. Topography influences forest composition in that it is one of the factors that determines how far below-or above-ground the water table will be. The woodlands that occupy low, boggy sites throughout the state are among the most striking examples of this control. Bog vegetation generally exists where the water table is at or slightly above the surface much of the year and where that water is poor in minerals. Cold, poorly aerated soils discourage thorough breakdown of organic matter, and therefore encourage the development of acidic peat deposits. Such sites are heavily dominated by Canadian (boreal) elements throughout Michigan--spruce, fir, larch, leatherleaf, blueberry--as these are the only plants that can be competitive on acidic, cold sites.
    The distribution of remnants of tall-grass prairie, found largely in southwestern lower Michigan, is also partly related to topography. Vestiges of an earlier prairie advanced into that part of the state from Illinois and Indiana during a period of warmer, drier climate, and these prairies and oak openings persisted on scattered patches of level or nearly level land of medium-or-better drainage until European settlement. Presumable, the low relief of these sites exposed them to a higher wind and fire risk. Once started by natural or human causes, fires could sweep across the flat terrain more easily than they could on the adjoining hillier landscape, resulting in damage to the invading woody vegetation and preserving the isolated prairie stands long after their former connection with the continuous prairie in Illinois and Indiana had been closed off by reinvading forests.

For the map below, what forest types are represented by blue and green?  Yellow is tallgrass prairie, red is mid-grass prairie, and tan is shortgrass prairie.

The image below is an interesting satellite composite of the percentage of forest cover in the Great Lakes region.  It shows nicely the large amount of forested land in the UP, and the abrupt change from forest to grassland in NW Minnesota.

Source:  Unknown

The map below is a choropleth representation of forest cover.

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Source:  Unknown

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Source:  Image Courtesy of Randy Schaetzl, Professor of Geography - Michigan State University

One way to evaluate the forest and vegetation resources of the state is to examine what they were like prior to European settlement.  The series of maps below will give you an idea as to the patterns of vegetation in Michigan in the early 1800's.  They start out more general, and become more detailed father down the page.


Source:  Unknown

Michigan lies largely within the northern hardwood forest region, with areas of the central hardwood region extending up into the southeastern part of the state, and with pines, aspen and swamp conifers occupying large areas in the northern part. Lines between these broad forest classifications are frequently irregular, and within each are many different types, phases, and temporary conditions, overlapping and changing with local variations of climate, soil, and moisture.
    Presettlement forest types have generally been described as primarily deciduous (hardwood) with oak, maple and beech in the southern lower peninsula, changing to mixed deciduous/coniferous species groups including maple, birch, hemlock, and pine further north. In reality, forest cover conditions were much more complex. The southern lower peninsula was dominated by large expanses of oaks where soils were drier, portions of savanna in the southwest, and maples, elm, and ash in wetter soils near the Saginaw Valley. Settlement removed the majority of mature hardwood forests throughout the south. Woodlots, seldom larger than 100 acres adjacent to farmland, continue to be fractured into smaller parcels near suburban areas.
    The Upper Peninsula is dominated by northern hardwood forests which occupy the better upland soils and which also occur in poorer quality on lighter soils. These stands include principally sugar maple, elm, basswood, and yellow birch, with beech present in the east half of the peninsula, and with hemlock and white pine often in mixture. The large areas of sandy plains found in many parts of the peninsula mostly support pines. Spruce, balsam, cedar, and tamarack (larch), the swamp conifers, generally occupy the poorly drained sites, while extensive areas of aspen occur throughout, principally on burned-over lands.
    In the Lower Peninsula northern hardwoods occupy the extreme northern part, extending in a broad band along the northwest side and into the central and southwestern sections. Yellow birch, hemlock, and white pine occur with less frequency or are entirely absent in these stands below the center of the state. Pine occurs principally in the broad sand plains and hills region in the north central and northeast parts. Aspen covers extensive areas of old burns throughout the north half of the Lower Peninsula, while the swamp conifers occupy the poorly drained and wet sites.
    The central hardwoods in general occupy the southeast part of the Lower Peninsula and are characterized by the oaks and hickories on the dry hilly soils, and by such species as sycamore, cottonwood, and silver maple on the heavier soils and bottom lands.

    Human intervention, such as harvesting, fire and clearing for development, has profoundly affected the composition of Michigan’s forest base. While the area of forest coverage has generally rebounded since the timber boom period of the last century, few regions of the State contain the same mixture of tree species that existed prior to settlement.

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This "placemat" map was produced by the Michigan Geographic Alliance and the Science/Mathematics/Technology Center, Central Michigan University, with funding from the U.S. Dept. of Education. For further information email Wayne.E.Kiefer@cmich.edu



Source: Atlas of Michigan, ed. Lawrence M. Sommers, 1977. 

How do we know so much about presettlement vegetation patterns?  Our data come form the US Public Land Surveyors' records and field notes.  Recall that most of the United States west of the original 13 Colonies was surveyed under the edicts of the Land Ordinance of 1785 and Northwest Ordinance of 1787. These laws provided for the division of unincorporated federal territory into six-by-six mile square townships which were further subdivided into 36 sections each one square mile. In assaying federal lands, contracted surveyors were also instructed to record things like the condition of the land, its potential for agriculture, etc. Most importantly for us, however, they also were required to note the species and diameters of two or four trees at each section corner (i.e., 8-16 per square mile), as well as major trees that fell on the section lines proper (usually 5-15 per squate mile section). That’s a lot of trees! And that’s a lot of paleo-vegetation information that we can use today to reconstruct past forests! These General Land Office (GLO) archives--aside from their valuable historical accounts and descriptions--have thus served as an important data source for the reconstructing presettlement vegetation and ecology in Michigan and elsewhere in the eastern United States.

Michigan's current vegetation has been dramatically changed by its inhabitants, as the map below shows.

This "placemat" map was produced by the Michigan Geographic Alliance and the Science/Mathematics/Technology Center, Central Michigan University, with funding from the U.S. Dept. of Education. For further information email Wayne.E.Kiefer@cmich.edu


1.  Oak-Savanna Community   
    Bur oak    Quercus macrocarpa
    Black oak    Quercus velutina
    Northern pin oak    Quercus ellipsoidalis

2.  Oak-Hickory Community   
   White oak    Quercus alba
    Black oak    Quercus velutina
    Red oak    Quercus rubra
    Pignut hickory    Carya glabra
    Shagbark hickory    Carya ovata
    Black cherry    Prunus serotina
    Hop-hornbeam    Ostrya virginiana
    White ash    Fraxinus americana
    Witch-hazel    Hamamelis virginiana
    Downy serviceberry    Amelanchier arborea
    Flowering dogwood    Cornus florida
    Eastern redcedar    Iuniperus virginiana
    Chinkapin oak    Quercus muehlenbergii
    Dwarf chinkapin oak    Quercus prinoides
    American chestnut    Castanea dentata
    Dwarf hackberry    Celtis tenuifolia

3.  Beech-Sugar Maple Community   
    Beech    Fagus grandifolia
    Sugar maple    Acer saccharum
    Red oak    Quercus rubra
    Basswood    Tilia americana
    White ash    Fraxinus americana
    Black walnut    Juglans nigra
    Tuliptree    Liriodendron tulipifera
    Bitternut hickory    Carya cordiformis
    Shagbark hickory    Carya ovata
    Slippery elm    Ulmus rubra
    Rock elm    Ulmus thomasii
    Alternate-leaf dogwood    Cornus alternifolia
    Blue ash    Fraxinus quadrangulata
    Downy serviceberry    Amelanchier arborea

4. Deciduous Swamp Community   
    Red maple    Acer rubrum
    Black ash    Fraxinus nigra
    Yellow birch    Betula alleghaniensis
    American elm    Ulmus americana
    Silver maple    Acer saccharinum
    Blue-beech    Carpinus caroliniana
    Alternate-leaf dogwood    Cornus alternifolia
    Nannyberry    Viburnum lentago
    Pin oak    Quercus palustris
    Swamp white oak    Quercus bicolor

5.  Pine Community   
    Jack pine    Pinus banksiana
    Red pine    Pinus resinosa
    Eastern white pine    Pinus strobus
    White oak    Quercus alba
    Northern pin oak    Quercus ellipsoidalis
    Black oak    Quercus velutina
    Pin cherry    Prunus pensylvanica
    Scarlet oak    Quercus coccinea

Parts of the text above have been paraphrased from C.M. Davis’ Readings in the Geography of Michigan (1964).

Parts of the text on this page have been modified from L.M. Sommers' book entitled, "Michigan: A Geography".

This material has been compiled for educational use only, and may not be reproduced without permission.  One copy may be printed for personal use.  Please contact Randall Schaetzl (soils@msu.edu) for more information or permissions.