Public Forests Managed for Ecological Diversity, Recreation

By Jim Low, Missouri Dept. of Conservation

First posted on 12-23-2009

Citizens who trust the Missouri Department of Conservation to manage their public forests wisely sometimes are shocked to find a timber harvest underway on a conservation area. The Show-Me State’s top forester says a better understanding of forest dynamics could prevent such reactions.

State Forester Lisa Allen has a long personal and professional history with forests. Growing up in Howell County, on the edge of the Devil’s Backbone Wilderness Area, helped shape her passion for forests. That love led her to bachelor’s and master’s degrees in forestry and a career that began as a resource forester in 1986. It continues to guide her work today as chief of the Conservation Department’s Forestry Division.

Along the way, Allen learned that, with the exception of a very few small areas, the idea of “undisturbed” forest in Missouri is an illusion.

“We have an abundance of wild, beautiful, even majestic public forest land in Missouri,” said Allen. “However, it is important to understand that these are not the same forests the first European settlers found when they came to Missouri more than 200 years ago. Most of the best public forests we have today are the result of careful management that followed early abuses.”

According to Allen, virtually all the state’s forests were logged in the late 19th and early 20th centuries. This logging often consisted of “high-grading,” removal of the most valuable trees, leaving less healthy, less valuable trees behind.

This “cut-and-run” logging made it likely that natural regeneration would produce inferior forests. That was not the worst of it, however.

The original round of logging often was followed by attempts to graze livestock or raise crops on land that was poorly suited for agriculture. Landowners commonly burned logged-over land each spring to prevent the regrowth of trees and encourage the growth of shrubby and herbaceous vegetation for livestock.

Robbed of its historic cover, the soil on steep hills eroded, depleting the land’s ability to support healthy forests like those that had vanished. When the Great Depression came, owners of abused forestland, who had been eking out livings on their acreage, no longer could pay property taxes. Many deserted their land, which reverted to public ownership.

By the 1940s, modern forestry practices and fire suppression took hold, and Missouri’s forests began a long-term recovery. Timber harvests were part of that recovery, but they were very different than earlier logging. Harvests were conducted to favor the growth of healthy, commercially valuable species. Careful attention to replanting and natural regeneration launched a gradual forest recovery. Six decades later, Missouri has more forest acres than it did prior to European settlement.

Recent surveys show that forest resources under Conservation Department management are growing at an annual rate of approximately 125 board-feet per acre, while it is being harvested at a rate of about 10.7 board feet per acre. The annual harvest rate on private land is 30.4 board feet per acre compared to a growth rate of 107.9 board feet per acre. Statewide, Missouri’s forest area has increased by about a million acres in the past 30 years.

Although forest management is very different in the 21st century than it was in the bad old days of cut-and-run logging, timber harvests are very much a part of the Conservation Department’s strategy for long-term forest health and wildlife diversity.

“The definition of conservation is wise use,” says Allen. “We definitely use our forests today, for everything from deer hunting and nature photography to watershed protection and wood products. The key is ‘wise’ use.”

The Conservation Department divides timber harvests on its land about equally between three types: even-aged, uneven-aged and thinning cuts.

Even-aged harvests involve cutting all or nearly all the trees from a particular tract. This leads to regrowth of a completely new forest with trees of the same age, hence the name. Reforestation under even-age management is simple in hardwood forests, where new trees grow from sprouts on the stumps of harvested trees.

The most common type of even-aged harvest used on conservation areas is a regeneration cut. Such harvests, also called clear-cuts, remove all the trees from an area at one time. Regeneration cuts accounted for 1,701 acres of timber harvest in fiscal year 2008. That is about 22 percent of the harvests conducted on conservation areas that year. Unlike Western forests, where clear-cuts can cover hundreds of acres, regeneration cuts in Missouri average about 15 acres.

Allen said she shares many Missourians’ concern about how regeneration cuts can affect the beauty of familiar places.

“Even-aged management is good for a forest when it is done right,” said Allen, “but there is no getting around the fact that it’s a shock to see a clear-cut where there was mature forest before. Just as we conduct timber harvests in a way that protects watersheds, we also work to protect ‘viewsheds.’”

Allen has ordered her staff to conduct critical reviews of the aesthetic effects of proposed harvests. In a directive to foresters, Allen wrote, “Regeneration harvests should only be used as a last resort for forest health, wildlife diversity and forest regeneration when in highly visible locations.”

Measures to soften the visual impact of regeneration cuts include leaving larger uncut buffers along roads, reducing the size and changing the shape of harvested areas or simply foregoing harvests altogether.

“We know that forests have values for Missourians that go beyond commodities,” said Allen. “It’s harder to put a price on a forest vista than it is to calculate the dollar value of a board foot of lumber, but that vista does have a value. To most of us, it’s priceless. We try to protect that, while still providing commodities that support jobs in the forest-products industry.”

Another type of even-aged tree harvest, known as shelterwood cutting, involves removing all trees in two or three harvests spaced out over a few years. This also results in a new forest where the trees are approximately the same age.

Shelterwood cuts simulate natural disturbance, such as a tornado or fire damage. They accounted for about 800 acres of timber harvest on conservation lands or about 11 percent of the FY 2008 harvest.

Shelterwood cuts work well for shade-tolerant tree species, whose seedlings benefit from the shelter of remaining trees. This even-aged harvest method provides abundant wildlife cover and food. It has the added benefit of avoiding the appearance of a clear-cut. However, it is more labor-intensive, causes repeated soil disturbance as logging equipment moves in and out of the area over a number of years, and it takes longer to achieve wildlife habitat goals.

Intermediate or thinning cuts account for another third of timber harvests on conservation land. They involve removing inferior trees to encourage more vigorous growth of the remaining trees. These also are known as timber-stand-improvement, or TSI cuts. The Conservation Department conducts intermediate cuts on approximately 2,500 acres annually.

The remaining one-third of timber harvests on conservation areas consists of uneven-aged cuts. These involve selectively removing trees of different ages and sizes at 5- to 10-year intervals to maintain a mix of large, mature trees and enough smaller trees to replace them as the older trees are harvested for commercial use.

Uneven-aged management is more time- and labor-intensive than even-aged harvest methods. Like shelterwood cutting, uneven-aged management involves multiple entries into the forest with logging equipment, which increases disturbance. It avoids the negative visual impact of regeneration cutting, but it does not create the same diversity of wildlife habitat.

The Conservation Department designates approximately 10 percent of the forest in each management compartment as old-growth timber. No harvests are conducted in these areas. The remaining 90 percent is actively managed with timber harvests. Allen said this policy serves several purposes.

The most important reason for active, harvest-based forest management is creation of diverse habitats that support a variety of wildlife.

“Some insects, fish, reptiles, amphibians, birds and mammals thrive in mature forest,” said Allen, “but by no means all. The ruffed grouse is a good example. It needs mature forest for mating and nesting, but grouse also need thick, brushy cover like what develops within a few years of a clearcut. That’s where they find food and escape cover. Grouse populations can’t survive in large tracts of undisturbed forest.”

Allen got a lesson in how hands-off forest management affects wildlife in her childhood haunts near the Howell-Ozark county line. After Congress created the Devil’s Backbone Wilderness Area in 1980, the Forest Service stopped all timber harvests on the 6,595-acre area. Deer, which browse low-growing vegetation throughout most of the year, were abundant there when Allen was young. That changed when active management of the forest stopped.

“The Devil’s Backbone Wilderness is a fantastic area,” she says, “but as all the timber on that area matured the forest canopy has closed. Herbaceous plants on the forest floor have dwindled. Hunters have a much harder time finding deer there nowadays. That is one reason we manage conservation areas for a diversity of forest types and ages.”

The fact that Missouri’s public forests are under careful stewardship that takes into account wildlife diversity, recreational opportunity and sustainable yield of forest products is good news. Less encouraging, said Allen, is the fact that Missouri’s privately owned forestland, which comprises approximately 80 percent of the state’s total forested acreage, is not as well-managed and productive as it could be. She said lack of management on private forest is responsible for this lost productivity.

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