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Wildlife Management Techniques

Active wildlife management in southern forests is very common (Dickson 2001). Substantial economic benefits are available for those willing to lease land for hunting or other recreation. Much industrial timberland in the South is leased for hunting. Game species, such as white-tailed deer, wild turkeys, bobwhite quail, and waterfowl, are primary management targets. Entire texts have been written describing practices that enhance game animal populations. This section describes common wildlife management practices in southern forests.

Maintenance of riparian vegetation along streamsides is almost universally considered essential by natural resource managers. It minimizes movement of sediment from upslope areas into streams (National Association of Conservation Districts 1994). In addition to improving stream quality, streamside buffers may benefit many rare and declining aquatic vertebrate and fish species throughout the Southeast. However, of even greater interest are benefits accrued by bird species. Streamside management zones, if widely implemented across a landscape, can support some vulnerable species. Because landbirds are not the sole concern when managing riparian habitat, the most effective conservation will balance economics with the needs of wildlife, including vulnerable neotropical migrants.

Streamside management zones (SMZ) are strips of various width along streams that are not managed like the rest of the stand. They usually contain mature deciduous trees, and timber management in these corridors either ceases or is scaled back in intensity. The primary function of SMZs is to provide a protective buffer that decreases logging impacts on streams, but SMZs also create structural diversity in stands. Wildlife use them for breeding and foraging, and as travel corridors (Machtans and others 1996). Brown-headed cowbirds are a major problem for other bird species in SMZs when the surrounding land has been recently harvested. Cowbirds utilize early successional habitat. During stand initiation after a disturbance, they often reduce nesting success of other species utilizing adjacent SMZs (Dickson and others 1993).

Melchiors (in press) and Wigley and Melchiors (1994) describe management opportunities as well as important caveats for interpreting existing data on wildlife use of retained riparian vegetation in actively managed landscapes. Existing data have been organized into three categories particularly useful for developing management recommendations: (1) streamside management zones in managed (usually short-rotation pine) forest stands, (2) riparian forest habitat in otherwise agricultural or developed landscapes, and (3) moisture/elevation gradients in largely forested landscapes (Melchoirs, in press). Current understanding of bird-habitat relationships in largely forested landscapes, especially in mountainous areas, indicate that forested riparian habitat is indeed important for supporting many species. Managers concerned with the plight of species depending on healthy forested riparian habitat should not place presently stable source populations at risk. Flexibility in managing riparian habitats is enhanced when large landscapes are under cooperative management. Widths of SMZs should be based on the nature of dominant land use patterns. If adjacent land is dominated mostly by mature or maturing stands, narrow SMZs may be adequate. In forests dominated by short-rotation plantation forest management, with many patches of early regeneration present during every decade, wider SMZs probably are needed. Finally, agricultural areas require the widest SMZs if vulnerable landbirds are an important goal for management. In the South Atlantic Coastal Plain, objectives for floodplain forested wetlands should suffice for SMZs.

In most, if not all, Southeastern locations, few important wildlife species would be served by narrow (10 to 25 foot) grassy streamside buffers. Such narrow and grassy riparian conditions may be adequate for minimizing erosion, consistent with the dominant land use. There is little argument among natural resource managers on the importance of maintaining forested riparian areas for wildlife in general, but several points are actively debated. These include: (1) adequate to optimal streamside widths, (2) acceptable structure and plant composition, (3) species to be targeted, and depending on the wildlife targeted, (4) the desired intensity of management consistent with balancing other priority land uses (Wigely and Melchoirs 1994). General guidelines given by Wigley and Melchiors (1994) include the correlation of SMZs with watershed size, the use of narrow SMZs on ephemeral or intermittent streams to promote diversity of bird communities in managed forests, and flexibility in SMZ width.

Costs to maintain wide SMZs can be considerable when timber production is the landowner's only or primary objective. Therefore, financial incentives, conservation easements, and partnerships through public-private programs are critical for stabilizing or enhancing riparian and aquatic habitat throughout the Southeast. Examples include the Farm Bill's Forest Stewardship program and the Partners for Wildlife program. Fortunately, many wood-producing industrial landowners and an increasing number of nonindustrial landowners are maintaining high-quality water and wildlife habitat, especially for landbirds. Nevertheless, recommendations for SMZ width and condition that go beyond State-sanctioned best management practices need to be presented to private landowners as optional treatments.

Cooperating partners should develop joint monitoring efforts in riparian habitats to better understand local responses by vulnerable species to SMZ treatments. Migration monitoring is likely to be most productive in SMZs. Results would add valuable information on timing and degree of transient passage through the South Atlantic Coastal Plain. Efforts to improve watershed management and riparian habitat condition should be monitored by collecting data along tributaries and main streams to the Flint, Chattahoochee, and Apalachicola. All these efforts should involve both public and private groups. Food plots often are claimed to increase game species abundance and health in forest lands that are being managed for hunting. Small areas cleared specifically for planting and woods roads or log landings are generally used. Specific crops planted depend on the site and the species being managed, but peas, winter wheat, ryegrass, and some commercial "wildlife mixes" are generally sown. Keeping small areas cleared has the benefit of creating ecotones, or transitional zones between habitat types, which many wildlife species use. It is debatable, however, whether perpetually cleared areas are as beneficial as those left to natural succession. Food plots may increase the carrying capacity for certain species, but substantial increases usually are not seen. The biggest benefits to hunters and wildlife managers are increases in wildlife observations and subsequent increases in opportunities to harvest game animals.

Green-tree reservoirs are sometimes placed in bottomland hardwood stands to enhance waterfowl habitat. These impoundments are flooded during the winter and early spring and have the potential to greatly benefit waterfowl. Optimally, water levels should fluctuate, increasing foraging potential for dabbling ducks. Hard-mast-producing tree species provide abundant food, and macroinvertebrates are present in great numbers. In addition to waterfowl, potential beneficiaries include reptiles and amphibians that are favored by fluctuating water levels. Warm water fisheries may also be enhanced by green-tree reservoirs. Annual growing-season flooding may decrease regeneration of desired tree species, but dormant-season flooding has little effect on timber quality or growth.

Ecological Variables

Chaotic events

Whatever management options are implemented, it is impossible to accurately predict the onset of natural catastrophic events. Wildlife populations are greatly affected by icestorms, windstorms, blight, southern pine beetles, oak decline, and a plethora of other landscape-altering phenomena. The American chestnut blight basically eradicated a major source of hard mast from the Southern Appalachians, with estimated reductions in hard-mast production of over 34 percent (Diamond and others 2000). Beech bark disease has virtually eliminated American beech from much of its native range. Acid rain has had detrimental effects on red spruce at high elevation in the Appalachians. Recently, southern pine beetle infestations in Kentucky eliminated all suitable habitat for red-cockaded woodpeckers. All of these birds had to be captured and relocated. All of these events have large, long-lasting effects on forested ecosystems and the wildlife populations that depend on them.

Landscape altering events have been taking place since the beginning of time. Many have led to species extinctions. In the case of American chestnut, oaks and hickories partially fill the void. Management strategies must be resilient enough to compensate when these events take place.

Soils and topography

Soils are of paramount importance in forest and wildlife management. They dictate, to a large degree, the species assemblages that occupy sites and are directly related to productivity (Hodges 1997). Although no strong correlations exist between site productivity and diversity, sites with highly productive soils tend to be more resilient (Baker 1997).

Silvicultural operations have the potential to impact soils. Harvesting with heavy equipment may compact and rut the soil. The ability of the site to rebound depends on soil type. Wet sites with clays that shrink and swell tend to rebound more rapidly after heavy equipment traffic than more silty soils.

With respect to biodiversity and productivity, little is known about the impacts of converting natural, mixed-species forest stands to pine plantations. In grassland ecosystems, natural prairie sites with high plant diversity are more productive than those with "improved" pastures that contain only a few species. Forests on productive soils with complex structural characteristics and species assemblages have the potential to support more diverse wildlife communities.