Pineywoods Wildlife Management
Aldo Leopold wrote in his 1933 textbook titled Game Management, "game can be restored by the creative use of the same tools which have heretofore destroyed it-ax, plow, cow, fire, and gun." The following is a brief discussion of how each of these tools can be utilized to manage habitat and wildlife in the Pineywoods.
Today, it is very important that land managers understand basic ecological principles of plant succession; plant growth; food chains; and water, mineral and soil nutritive cycles as they affect range, wildlife, and grazing management. In addition we should know and recognize the basic needs and preferences of the livestock and wildlife species for which we are trying to manage. It is equally important to manage for a high level of plant succession and quality wildlife habitat using the basic tools of grazing, rest, fire, hunting, animal impact, disturbance, and technology. This not only produces high quality habitat and animals, but also can lead to more stable conditions during stress periods such as droughts and winter.
The chainsaw and other mechanized equipment have long since replaced the axe. Although the tools have changed, the habitat quality of forested areas can be maintained or improved through proper management. As discussed in the Historical Perspective, the forests of today are very different than those present during pre-settlement times. Due to the economic value of pine timber, many landowners are involved with intensive timber management. Although revenue from timber production may be the primary focus of the landowner, the economic value of wildlife relative to timber production has improved significantly. Therefore, it is easier for the landowner to justify giving wildlife consideration when management planning. Forested areas can be managed to produce wood fiber, while at the same time providing concessions for wildlife. Management activities that increase habitat diversity are valuable for game as well as nongame species. Timber management strategies can be grouped into 2 categories, even-aged and uneven-aged.
Even-aged management is defined as the application of a combination of management actions, which results in a timber stand comprised of trees that are the same age. Harvest methods used to generate even-aged stands are clearcut, seed-tree, and shelterwood. A clearcut results in the removal of all merchantable timber and is usually followed by site preparation and planting. Both the seed-tree and shelterwood methods rely on natural regeneration. A seed-tree operation results in the removal of all merchantable timber, with the exception of a few, well-spaced high quality trees with good seed production that will be relied upon to regenerate the stand. Approximately 8-10 trees per acre may be retained for seed production. These seed-trees may be harvested after adequate regeneration has become established, or may be left indefinitely. The shelterwood method results in the removal of 40 to 60% of the merchantable timber. The residual trees are relied upon for seed production and seedlings become established in partial sunlight under the shelter of the residual trees. Similar to the seed-tree method, residual trees may be harvested after adequate regeneration has become established.
Regardless of the method used, consideration should be given to the size, shape, and distribution of the harvest area prior to the final harvest operation. Regeneration cuts (final harvest cuts) should not exceed 50 acres. Stands should be irregularly shaped to increase edge. In order to produce a mosaic of stands of various ages in close proximity, stands should not be harvested until the adjacent stand is at least 5-7 years old.
During harvest, streamside management zones (SMZ's), or a band of uncut timber, should be retained on each side of stream channels within the regeneration area. The SMZ should be a minimum width of 66 feet on each side of the channel. Along intermittent and perennial streams, widths of 100 feet or more are preferred. To provide maximum benefit to wildlife, these minimum widths should be extended to an identifiable natural break in topography (crest to crest), or to an area defined by the presence of hardwoods. In addition to protecting water quality, these areas increase diversity, provide valuable mast production, and serve as wildlife travel corridors. In addition to SMZ's, clumps of upland hardwoods should be retained to create additional diversity.
Prior to regenerating an area, some level of site-preparation is usually necessary. There are many site-preparation techniques available. The more intense site preparation techniques tend to favor grasses and herbaceous vegetation, while less intense methods tend to favor woody species. When regenerating artificially (planting), seedlings should be planted on a spacing of at least 8 feet by 10 feet. A wide spacing delays canopy closure, which results in the shading out of valuable understory vegetation.
After canopy closure has occurred, the production of grasses, forbs, woody vines, and low growing shrubs greatly declines due to the lack of sunlight. At this point, the pine plantation loses much of its value to wildlife, except for cover. Stands that have reached canopy closure should be thinned. Thinning will not only increase the amount of sunlight reaching the forest floor, but will also reduce competition among the residual trees. Thinnings can be applied periodically throughout the life of the stand. Thinning operations should remove poor quality pines and undesirable hardwood species, while favoring the high quality pines and valuable mast producing hardwoods.
Even-aged management is relatively simple to apply. However, since many private landowners find even-aged management (especially clearcutting) objectionable, this management strategy may have limited application on the small acreages typical of many east Texas landowners.
Uneven-aged management is defined as the application of a combination of management actions that maintains several age-classes and tree sizes within a timber stand. In order to produce a sustained yield of forest products, uneven-aged management results in continuous canopy coverage, recurring regeneration of desirable species, and the orderly growth and development of trees in several diameter and age-classes. Regeneration is through natural methods.
Under an uneven-aged management strategy, individual trees (single-tree selection) or small groups of trees (group selection) are selectively harvested every 5-10 years. An area properly managed under single-tree selection results in a forest that is comprised of evenly distributed large, medium, and small trees of various ages. This system requires the removal of trees of all ages and sizes in order to maintain a healthy stand. To prevent degradation of the stand, the application of this harvest strategy requires the expertise of a forester experienced in uneven-aged management. Diameter cutting (cutting all trees larger than a predetermined size, rather than using tree age as criteria) or "high-grading", can result in a stand comprised of inferior trees after a few cutting cycles and should be avoided.
In order to replace individual trees that are removed, seedling establishment in the openings created by tree harvest is a critical component of uneven-aged management. Under this system, a more or less continuous overstory is maintained. Therefore, tree species that require direct sunlight to regenerate, such as pines, do not fare as well as other species that require less direct sunlight. In order to maximize the amount of sunlight that filters through the overstory and successfully reaches the ground, the more shade tolerant species in the midstory and understory may need to be controlled. Prescribed fire can be used to control small, competing species. Since the effects of fire will be short-lived, frequent fires are necessary. This poses a problem for pine regeneration, as pine seedlings (except longleaf) are unable to withstand frequent burning. The prescribed fire interval necessary to control competing vegetation often is too short to ensure adequate survival of pine seedlings. Therefore, successful single-tree selection management in pine stands often requires the use of herbicides or mechanical means to control competing species.
The landowner's objective should dictate the level of control of competing vegetation. Intense control that favors pines over other species, results in a stand of higher economic value. Conversely, less intense control results in a mixed stand that is of lower economic value, but higher wildlife value.
Unlike single-tree selection, the group selection strategy involves the harvest of trees in groups or patches. The size of the group may range from an area occupied by a few trees up to a few acres. Group selection creates larger openings that are more conducive to pine regeneration, than those created under single-tree selection. Prescribed fire can be used in areas managed under the group selection strategy. However, burning may be less efficient and more labor intensive due to the need to protect the scattered "patches" that are too young to burn.
Group selection management increases habitat diversity by providing small, scattered patches of micro-habitats in various stages of plant succession over a small area. Early successional habitat is made available in close proximity to habitats in more advanced successional stages.
Group selection may be a useful management scheme for many non-industrial private landowners since it provides a diversity of wildlife habitat within a relatively small area. Group selection also minimizes or reduces the negative visual impacts that are associated with some even-aged management strategies.
As with even-aged management, proper uneven-aged management should allow for a continuous component of mast producing hardwoods.
Effective habitat management often requires the availability and proper use of an array of management "tools". Due to varying management objectives, no one tool, or timber management system, is the most appropriate for every situation. Misuse of any timber management strategy can cause degradation of habitat quality. Land managers should develop well-defined objectives, and select and properly implement the strategy that is the most appropriate for their management needs.
Prior to settlement, longleaf pine forests, with grass dominated understories, dominated the uplands in southeast Texas. Due to conversion to loblolly and slash pine forests, and suppression of fires, very little of this habitat type remains today. Landowners involved with pine regeneration on suitable sites are encouraged to consider restoration of the important longleaf pine ecosystem.
The above management guidelines pertained primarily to the management of upland pine stands. Bottomland hardwood stands provide valuable wildlife habitat. Unfortunately, the quantity of bottomland hardwoods has greatly decreased. Bottomland hardwood forests should be managed to provide a continuous supply of hard mast and cavities. Peak acorn production occurs in stands that are between 40 and 100 years old. Therefore, the majority of the stands should be at least 40 years old and long rotations (80+ years) are encouraged. In established stands, partial cuttings (thinnings) can be made on a 10-year cutting cycle. Thinning will promote vegetative growth in the understory and encourage vigorous growth in the residual trees. Thinnings should improve the quality of the stand. As with upland pine management, thinnings should favor high quality mast producing trees and remove low quality trees or undesirable species. Landowners should not let unscrupulous individuals "high grade" the stand. High-grading results when the high-quality trees are removed and the malformed or defective trees are left.
When regenerating bottomland hardwood stands, group selection or patch clearcuts are generally preferred. The two techniques are similar in that all stems are removed during the final harvest and the new stand develops from sprouts and advanced regeneration present prior to the harvest. The main difference relates to the size of the opening, with group selection being the smaller of the two. Due to the complexities of bottomland hardwood management a person experienced in the management of bottomland hardwood stands should be consulted prior to conducting management activities.
If wildlife and water quality are of concern, bottomlands should not be converted to pine, pasture, or agriculture.