How much forested land does Wisconsin have?
Wisconsin’s total land area is 34.7 million acres. Land growing trees covers 16 million acres or 46%. Most forested land is in the northern part of the state.
How old are Wisconsin’s forests?
Many southern Wisconsin forests were cleared for agriculture by the late 1800’s. Forests in the north were heavily cut for timber by the early 1900’s. Therefore, almost all the mature trees you see today are less than 125 years old. Thousands of acres of pine were planted across the state in the 1930’s by the Civilian Conservation Corps.
Who owns and cares for Wisconsin’s forests?
Most forested land in Wisconsin…57%…is owned by individual landowners like farmers, home owners, hunting partners, investors and others. 32% is owned by federal, state, county or tribal governments. 11% is owned by private corporations.
Deforestation is a big concern. How much forested land does Wisconsin lose every year?
Unlike some parts of the world, Wisconsin has been gaining forest acreage, not losing. After heavy logging early in the 20th century, much land was burned and converted to agriculture. But, since the 1930’s, much marginal crop and pastureland has been planted with trees so the state now has more forestland than at any time since inventories began in 1936.
But I see log trucks on the road all the time. This harvesting must be having some effect.
Of every 1,000 live trees over ten feet tall in Wisconsin this year, 80 will die from severe weather, insect damage, crowding, disease or old age. Only 4 of the thousand will be harvested by loggers. However, 98 new trees will grow past the ten foot mark during the year. Therefore, in Wisconsin, annual wood growth exceeds harvest for most species.
Still, can’t we just get our wood products from somewhere else and leave Wisconsin’s woods alone?
We could, but the forest most hospitable to the greatest diversity of plants and animals is one with young, old and medium age trees, and a variety of tree species. Since fires, insects and tree diseases are better controlled today, one way to make room for younger trees is to harvest those nearing the end of their life cycle. Cutting trees properly not only mimics natural events like fire, but provides society with jobs and hundreds of useful wood products. The alternative would be to use nonrenewable material or wood imported from places that, unlike Wisconsin, do not manage forests in a sustainable fashion.
How much wood does the average person use in a year?
About 1,664 pounds, or one log 18 inches across and 25 feet long will meet the needs of an average person annually for building supplies, newsprint, printing and writing paper, tissue paper, paper towels, product packaging and mail. Also, there are hundreds of products you might not think contained wood fiber like toothpaste, football helmets, scotch tape and milkshakes.
The population is growing. What guarantees that harvests won’t rise again to destructive levels?
Like any profession, modern forestry and wood production have become highly evolved. Many sensible practices unheard of years ago are now common, such as recycling. Technological developments allow wood products to be manufactured from smaller pieces of wood, thus using more of each tree and reducing waste. In addition, conservation and forest health are now top priorities. Modern forest planning in Wisconsin balances wood harvest with other forest uses such as wildlife habitat, recreation, erosion control, biological diversity and other needs.
After trees are cut, how do they grow back?
Forests can regenerate when seeds drop or blow in from nearby trees, or when seeds are carried in by birds and animals; by the planting of seedlings; by seedlings which sprout from roots or stumps left after harvest; or by existing seedlings which cannot thrive in the shade of larger trees, but once allowed sunlight, will grow quickly. Preharvest planning and proper harvest techniques assure that one or more of these methods will succeed.
Are there any rules and regulations which govern the use of forestland in Wisconsin?
Yes, but they do not apply uniformly to every parcel. Most government and industry owned land is managed according to carefully written plans which specify environmental protections, insect and disease control, recreational uses of the property and wood production. Parcels of individually owned forest land are subject to some environmental restrictions on harvesting near lakes or streams, and many owners voluntarily observe “best management practices”. One state program offers landowners a property tax deferral in exchange for certain forest stewardship practices. Much of Wisconsin’s forest land is third party certified and therefore must adhere to forest certification standards.
It sounds like Wisconsin’s forests are pretty healthy. Is that true?
Yes. Overall, Wisconsin’s forests are in very good shape. Major threats like fire, insect infestation and tree diseases are generally well controlled. Regionally, there are occasional problems with insects like the gypsy moth or jack pine budworm, or with tree diseases like oak wilt or white pine blister rust, all of which can damage or kill trees. However, currently the greatest threat to forests statewide comes from converting forested land to housing, highways and other development.
I’ve noticed lots of dead white birch trees. What happened?
White or “paper” birch trees are among several species which are relatively short-lived (70-80 years). They are a sun-loving species and many of the trees you see today sprouted in the early 1900s after extensive logging followed by fire cleared the land. Now, these trees are simply at the end of their natural life. For some, their life span was shortened by drought. The stress of too little moisture was sometimes compounded by insect damage from the bronze birch borer and birch leaf miner.
What about other dead trees? Is it just old age?
Not always. Forests are constantly changing and the death of individual trees is just part of “mother nature’s” forest management plan to make way for new growth. Often, a dead tree gives clues to what killed it…old age, crowding or competition for light from surrounding trees, high wind, flooding, drought, insect or animal damage, or disease caused by fungi.
Is it generally true that the taller a tree, the older it is?
No. Different species grow to different heights at maturity and not all trees live to the same old age. Jack pine, for example, grow to a maximum height of 50 to 70 feet and live only 50 – 60 years. White pine, though, grow to 120 feet or more and live to 250 years. There can even be big differences in height among trees of the same species and age depending on the amount of sunlight, moisture, and soil nutrients the tree gets, the genetic makeup of the seed, and competition from neighboring trees.
Do tall trees really have deep roots?
No. 90% of any tree’s roots are in the top 12 inches of soil. Roots grow mostly sideways and can extend up to three times the height of the tree. The shape of a whole tree actually resembles a wine glass set on a plate, with the plate representing the root system. Root growth can occur any time the soil temperature is above 32º F.
How many leaves does a tree have?
It depends on the tree’s species and age, but a mature, healthy tree can have 200,000 leaves. During 60 years of life, such a tree would grow and shed 3,600 pounds of leaves, returning about 70% of their nutrients to the soil.
Why do certain tree species seem to dominate in certain parts of the state?
Trees, like any plants, thrive for many reasons. Most important is soil, sunlight and moisture. Centuries of erosion have determined the composition of soil in some parts of the state. Receding glaciers have left different soils elsewhere. Wisconsin also has certain zones or regions with distinctive weather and climate patterns. These physical factors, along with the amount of sunlight reaching a tree, mostly determine what species grow where. Biological factors like tree genetics and human (fire, planting, harvesting) or animal (seed distribution, browsing) intervention also play a key role.
Why do leaves change color in autumn?
Less daylight and cool (but not necessarily freezing) fall temperatures result in less production by leaves of green pigment (chlorophyll). Consequently, other leaf pigments like yellow (xanthophyll), orange (carotene) and red (anthocyanin) become more prominent. The intensity of color in a leaf depends on the amount of sugar stored in the leaf and the amount of autumn sunlight it gets. Brown pigment (tannin) remains after all other pigments have disappeared.
Most trees lose their leaves each fall, but some keep them over winter. Why is that?
In spring, new leaves and twigs grow out together and are firmly attached. In fall, a specialized layer of “abscission” cells form between each leaf and twig, cutting off water to the leaf and killing it. Then the abscission cells die and the leaf falls off. In young oak trees, however, for reasons that are unclear, abscission cells form but do not complete their work. Therefore, oak leaves often stay connected to the twig until pushed off by new leaf and twig growth in the spring.
Do forest animals prefer certain tree species, or is any type of forest O.K.?
Most species of birds and animals have a preference for certain forest type, and often prefer a specific tree species. Wolves and yellow-bellied sapsuckers, for example, generally prefer large areas of forest. Grouse and snowshoe hare prefer younger forests which exist after fire or harvest. A forest with oak trees is more hospitable to squirrels and wild turkey than one without.
Does anyone pay attention to trees in cities?
Definitely. Many Wisconsin communities have active “urban forestry” programs. In fact, Wisconsin ranks 5th nationwide in the number of communities designated “Tree City, USA” by the National Arbor Day Foundation. Urban foresters plant, prune and remove trees in order to promote several benefits: trees clean the air by absorbing carbon dioxide and releasing oxygen; cool by providing shade; prevent water pollution by holding soil in place and absorbing runoff; and trees beautify. Properly managed, city trees can thrive. The tree with the largest circumference of any in the state is located in the city of West Allis!
Where can I get more information about Wisconsin forests?
For national forests:
United States Forest Service
For state forests:
Wisconsin Department of Natural Resources
For county forests:
Wisconsin County Forest Association
For industry owned forests:
Wisconsin Paper Council
For privately owned forests:
Wisconsin Woodland Owners Association
*These questions and answers were developed as a project of the Wisconsin Governor’s Forestry Council. Reprinted by permission.
For a copy of the booklet “Questions and Answers about Wisconsin Forests” contact any of the addresses above.