• Topics: Wildlife Ecology and Conservation  | Squirrels  | Deer  | Wildlife Forages  |  Tanner, George W  | Marion, Wayne R  | Werner, Matthew 

Management of Pine Forests for Selected Wildlife in Florida¹

Pine flatwoods are common in the southeastern Coastal Plain and extensive in Florida (Figure 1). This forest type is increasingly used for timber production. As the total number of forested acres in Florida diminishes, needs for forest products are increasing. At the same time, there are other resource needs that must be satisfied. Wildlife habitat is an excellent example. Although these two needs can be compatible in multiple-use forests, they are frequently seen as competitive. Forests and wildlife are linked together since many wildlife species are directly dependent upon the forest. Good forest management is not necessarily good wildlife management and vice versa. Most forest management practices affect wildlife habitat and result in changes in the wildlife community.

Figure 1. 

This publication is aimed primarily at the private forest landowner in Florida. Although these landowners generally hold small parcels compared to industrial forests, such holdings represent the majority of forested lands in the state. Florida pine flatwoods are probably the most intensively managed for commercial purposes, and for this reason, management options favoring wildlife in pine flatwoods will be emphasized. We will attempt to illustrate ways in which timber and wildlife management can be successfully combined in an integrated approach consistent with ecosystem functions to fulfill multiple resource objectives.

WHAT ARE PINE FLATWOODS?

Flatwoods are typically found on poorly drained, sandy soils intermediate in moisture content between wetter bottomlands and drier uplands. Overstory of these woodlands consists mainly of longleaf, slash, and loblolly pines, although pond pine does occur in local areas. Intermixed with the flatwoods are small bayheads, many cypress domes, prairies, marshes, and hardwood swamps.

Fire originally played a major role in determining the overstory composition of flatwoods, since longleaf pines are relatively fire-tolerant and slash pines are not. Fire suppression by man has greatly altered the balance of ecological forces and caused obvious changes in natural vegetative communities. More recently, conversion of natural longleaf, slash pine, and hardwood forests to slash and loblolly plantations throughout the southeastern Coastal Plain has even more strongly altered natural vegetative patterns.

The shrub layer of flatwoods forests includes blackberry, dwarf huckleberry, fetterbush, gallberry, saw palmetto, and wax myrtle. These are all evergreens that produce fruits and berries that are important wildlife foods. Grasses on the flatwoods forest floor include broom-sedge, chalky bluestem, Indian grass, panicum, paspalum, and wiregrass. Associated herbs include beggarweed, deer tongue, grassleaf gold aster, partridge pea, and rabbit tobacco. Florida flatwoods are frequently grazed by domestic livestock and are inhabited by a variety of wildlife species.

FLATWOODS WILDLIFE

The term wildlife includes all of the free-ranging, wild vertebrate species inhabiting an area. In the southeast, there are about 400 resident species of mammals, birds, and reptiles. Of course, no one parcel of land will support nearly as many as 400 species. In fact, each species, and sometimes each life stage of a species, requires a unique set of habitat conditions. Consequently, different management techniques favor different wildlife species. Stated as a basic ecological concept, we can say that habitat varies in time and space, and as habitat changes, or is changed, so do the species of wildlife and their abundance. It is not realistic to think that all wildlife species in an area will react as one to a particular management practice. There are a wide range of responses to each practice, depending on the species being considered. In general, the larger a parcel of land and the greater the variety of habitat types present, the greater the variety of wildlife species that can be supported there.

There are many reasons for managing wildlife. Among these reasons are preservation of endangered species and recreational activities, such as hunting and wildlife observation. Preservation of endangered species, such as the red-cockaded woodpecker, requires careful management of specific habitat types suited to those species. Wildlife also is an important recreational resource. Throughout the southeast, approximately 10 percent of resident birds and 20 percent of resident mammals are considered game species suitable for hunting. Leasing of hunting rights on private forested land is becoming a more typical means of gaining access to game. Hunting leases can provide substantial annual income, whether it be supplemental or primary, for the owner of well-managed forestlands.

red-cockaded woodpecker. 

Nationally, only about 20 percent of wildlife-related recreational activity involves hunting. Americans involved in wildlife observation (e.g. bird watching) outnumber Americans involved in hunting by more than two to one. In addition to resident wildlife species, the forests of the southeastern United States support a massive influx of migratory bird species between the fall and spring each year. These are but a few of the worthwhile reasons to manage forests to favor wildlife.

CHANGING FOREST STRUCTURE FOR WILDLIFE

The ability to produce timber and pulpwood in southern pine forests is continually improving. Examples of new techniques include genetic stock improvement, planting of superior seedlings, and use of various herbicides and insecticides. These developments help the forester to meet the growing demands for pulp and timber. But how do these developments affect wildlife?

Diversity

Diversity is a fancy term to describe variety or differences in many things. The techniques and developments listed above tend to reduce the vegetative diversity in the flatwoods forest. As the structural diversity (height differences in vegetation) of forests is reduced, so is their capability to support various and abundant wildlife species. Forest structural diversity is considered to be the main determinant of the number and abundance of wildlife species. Every species has a unique set of habitat requirements (food, cover, water, and arrangement). Maintenance or enhancement of structural diversity, both within and among forest stands, maintains or increases the types of habitats available for wildlife.

Within-Stand Diversity

Establishment of even-aged plantations, while facilitating timber production and harvest, has greatly reduced within-stand structural diversity. Low- and mid-story vegetation often are poorly developed in such stands, especially after closure of the pine canopy. Each tree species has a unique growth form. By limiting a forest stand to one or two species, structural diversity is further reduced.

Temporal diversity is created when there is a variety of plant species present that provide wildlife food at different times of the year. A variety of food sources also assures that if one crop fails, there will likely be another that does produce.

Snags are another component of forest structural diversity that are important as wildlife habitat. A snag is a standing dead or dying tree that provides perching and nesting sites for a variety of animals. Snags also are rich in insects, important food sources for many animals. It is most useful to leave a few snags standing in the forest. Even snags left in clearcut areas increase the diversity of bird species in the cut area.

Among-Stand Diversity

The creation of among-stand diversity presents the greatest opportunity for wildlife population enhancement in multiple-use forests. It seems likely that even-aged pine plantations are here to stay for the next few decades in Florida. However, even-aged plantations can be successfully managed for selected wildlife if horizontal, or landscape, diversity is developed and maintained. This is achieved through the intermingling of stands of different ages and types.

Landscape characteristics such as topography, soil types, and related physical and biological features should dictate the design of multiple-use forests. Management blocks are best defined on the basis of watersheds and drainages, not on historical or political boundaries, which very likely have no ecological basis. Allow the site to dictate the tree species to be managed. For instance, hardwood trees should be left or planted in areas normally not suitable or productive for pines. Wetlands like swamps, bottomlands, and pond edges that do not support pines should be left alone and intact. Hardwood forests normally produce and support two or more times the wildlife populations of coniferous forests. As such, they are an important aspect of among-stand forest structural diversity.

Consideration should be made when planning the locations of habitat units for the life-cycle requirements of larger wildlife species. Value to wildlife will be increased by insuring that these units are sufficiently large to provide for breeding territories and home ranges of species being considered. It is also common for wildlife species to make daily and seasonal shifts in habitat use, thus it is essential to provide habitat corridors and travel lanes to allow movements between similar habitat units and across open areas. These habitat corridors are also useful in fostering the recolonization of isolated patches of habitat, especially for terrestrial forest-dwelling animals.

Edge Effect

An important concept in ecology that can aid the manager interested in wildlife is that of edge effect. Edge effect occurs in the zone where two different habitats meet — sometimes called the ecotone. Both habitats contribute plant and animal species to the edge zone, and the cumulative effect makes the edge more valuable to wildlife than either habitat alone.

Quality edge zones are created by the side-by-side placement of two dramatically different habitats for a period of at least several years. For instance, two adjacent clearcut areas will generate a trivial amount effects, such as increased erosion. A clearcut area next to a mature stand might create maximum edge effect one year only to have it diminish to zero the following year if the adjacent stand is cut. The highest quality edge effect will occur if a clearcut area is placed next to a mid-rotation stand. Long or irregularly shaped clearcut areas (C and D in Figure 2) will create more edge effect than square or circular ones (A and B in Figure 2 ). If the edges of the cut follow irregular contours, the edge effect will be even greater.

Figure 2. 

Coverts are formed by the interfacing and interaction of three or more habitat types at one point. Coverts are even better than edge zones for some wildlife species.

Access roads, powerlines, and firelanes also are habitat features that can be managed to greatly enhance landscape diversity. High-nutrient forage plans can be seeded in these areas to provide quality food for wildlife. Irregular, as opposed to straight, roads provide more of this valuable forage, as well as increasing edge zones. Open areas like these also are important insect habitats. Limiting access of people to these areas will encourage their use by wildlife.

In summary, a mixture of relatively small, different but even-aged pine stands at various stages of growth, intermingled with each other and with natural communities (streams, hardwoods, cypress domes, etc.) will provide adequate quantity and quality edge effect and increase among-stand forest structural diversity.

DEVELOPING A MANAGEMENT PLAN

The forest is constantly changing. Many changes are subtle and gradual, such as the replacement of plant and animal species by other species. You may not notice these changes until they have already happened, but they are always occurring — a process known as ecological succession.

Forest and wildlife management often involves changing the natural course of succession to produce stand and habitat conditions that meet your needs and interests. In essence, management practices provide you with the ability to somewhat control which native wildlife species will be present on a forestland. A management plan helps to do this.

Several steps are necessary in developing a management plan. First, identify your objectives, needs, and interests both in short- and long-term goals. How often do you want to harvest trees? What types of wildlife do you want to encourage? How intensive will your management input be?

Next, inventory the habitats present on your land, so that you know what you have to work with. Most likely you will find pine flatwoods and/or bottomland hardwoods, and other habitat types will add important diversity to your forest. Create management blocks based on the habitat types that you have identified.

To manage for specific wildlife, it is essential to know the habitat requirements of the species in which you are interested. This step may require further reading, or contacting Cooperative Extension Service personnel. Be sensitive to wildlife needs for cover, food, water, and the arrangement of these resources. Animals depend on insects as food sources, so in this situation, the use of insecticides to suppress insect populations can be undesirable. Also protect the animals' watersheds by keeping streams well vegetated, and by using procedures to prevent soil erosion during harvesting and other operations.

Once you have determined what you want to do, the following section on silvicultural, or forest management, practices should help you decide how to achieve your goals.

SILVICULTURAL PRACTICES AND THEIR EFFECTS ON WILDLIFE

In general, the result of intensifying forest management in recent years has been a reduction of within-stand forest structural diversity. As a result, several habitat characteristics of importance to wildlife are being lost. The development of among-stand diversity is an alternative that can provide partial compensation for the loss of within-stand diversity. In this way, habitat conditions suitable for a wide array of wildlife can develop. Six common timber management practices and their effects on forest structural diversity and wildlife are explained (see Table 1 ).

Site Conversion

The conversion of natural longleaf pine or hardwood forests to slash or loblolly pine plantations generally has drastic effects on wildlife. Site conversion typically results in the loss of both the naturally diverse characteristics of the original forest type and the among-stand features created by the intermixture of different forest types. Natural longleaf pine forests in the southeastern Coastal Plain seem to be superior as wildlife habitats when compared with either natural or planted stands of slash and loblolly pines. Longleaf pines support greater numbers of insects, making them more attractive to insect-eating wildlife.

Site conversion. 

Did you ever hear the phrase "Mother Nature knows best?" By leaving most tree species and natural plant communities intact, you can usually retain valuable diversity over broad areas. The more a stand is changed from its natural situation, the more management efforts will be required to put it back into its previous condition. Wet areas, such as cypress domes, bayheads, swamps, marshes, etc. that are not suitable for pine growth, provide important wildlife habitats and refuges. Even small areas of 10 to 12 acres can be very important to wildlife. On the other hand, drainage of wetlands and conversion to conditions suitable for pine growth are generally detrimental to native wildlife.

A noteworthy point related to site conversion involves pine plantations that have been planted on "old-field" sites. Old-field sites are ones formerly under agricultural cultivation. In general, old-field sites yield greater pine growth and less understory growth than previously non-cultivated sites. Development of understory vegetation is typically minimal in old-field plantations due to the lack of seeds in the soil. Studies show that there is a steady decrease in understory deer browse as old-field plantations grow older. The peak browse value of plantations on previously forested sites occurs in 5- to 10-year-old stands. The lack of structural diversity of vegetative layers in old-field plantations results in low within-stand diversity generally thought to be less attractive to wildlife than plantations on previously forested sites.

Clearcutting

Perhaps no forest management practice has caused more controversy on a nationwide basis than clearcutting . Clearcutting is the forestry practice that involves the harvesting of all commercially valuable trees in an area. In the Southeastern Coastal Plain, flatwoods clearcutting is the most common technique used in timber harvesting. No other management practice has more immediate and dramatic effects on animals and their habitats. For example, clearcutting typically excludes from a site all birds and mammals that feed and nest in crowns of trees. The degree of impact depends on the age, plant species present, stocking density, and size and shape of the stands removed. In northern Florida, approximately 40 percent of the breeding forest bird species are cavity-nesters, and clearcutting has drastic effects on local populations of these birds. Competition among animals for nesting cavities is intense; thus, clearcut, short-rotational management systems represent potential limiting factors for these species. Whenever possible, snags and trees with cavities should be left standing to fulfill the requirements of cavity-dwelling species of wildlife.

clearcutting. 

Generally, very few wildlife species are common to a site both before and after a clearcut. Clearcutting may be as favorable for some species as it is unfavorable for other species. Removal of the shading effects of the forest overstory allows an increased growth of understory vegetation, which may significantly benefit ground level feeders, such as white-tailed deer, bobwhites, eastern meadowlarks, cottontails, and wild turkeys that require open conditions and early successional stage plant communities. Production of ground-level fruits available for consumption by wildlife is greater during the first few years following clearcutting. Studies of Florida flatwoods demonstrate that clearcuts and edges of clearcuts also are important habitats for wintering bird species.

The size and shape of a clearcut site determine the degree of impact on wildlife. Generally, large square or circular cuts of more than 250 acres are not used extensively by the majority of resident animals having small home ranges. Large animals, such as deer, use only the outermost 100 yards of large clearcuts, where forest cover is nearby. The center of large clearings may go largely unused by wildlife. Smaller, elongated clearcut areas of less than 100 acres are usually more favorable for wildlife, since they allow greater use of the food sources within clearings and create more edges. Since long, narrow clearcut areas include more territories and home ranges of animals, they allow more individuals to benefit from the close proximity of food and cover.

There are alternative regeneration methods that may be used instead of clearcutting and replanting with seedlings. The two-cut regeneration system, or shelterwood, is an inexpensive, natural way to establish young pines prior to the harvesting of all mature trees. The first cut is made a few years before the final harvest, and prescribed burning is used to prepare the site for seedling establishment. The stand is thinned heavily, leaving only the best formed trees to provide seed for regeneration. The remaining trees are harvested after a uniform growth of young pines has appeared.

The seed tree regeneration system is similar to the shelterwood system, except that it leaves fewer trees standing. The main disadvantage is that the small volume of timber left may be difficult to sell. Both of these systems are valuable in that they generally result in increased habitat and wildlife diversity. Abundant ground level forage is produced and substantial bird populations are frequently supported. However, germination, spacing, and survival of seedlings are unpredictable.

Clearcutting usually is followed by a number of treatments that prepare the site for the planting of tree seedlings. These treatments may include any combination of the following: burning or chopping of debris and piling it in windrows with a K-G blade, stump removal, herbicide use, harrowing, bedding, and ditching. The combination and intensity of these site preparation techniques determine their impact on wildlife. Very intensive site preparation practically eliminates the existing plant communities from the site, and establishment of desirable wildlife foods is consequently delayed.

Site Preparation

The length of time that it takes for growing pines to dominate a site also depends on the intensity of site preparation . This is an extremely important point in determining the species of wildlife that will be supported. When the pines are young and the sparse crowns allow sunlight through, the plantation may typically be used By wildlife species that live in early successional habitats. These include bobwhites, cottontails, cotton rats, and sparrows. Young forests also supply abundant foods for deer and turkeys. These habitats and animals decline as the pine stand approaches crown closure. After closure and before thinning or burning occurs, a pine plantation provides few food plants and little more than escape and nesting cover for many wildlife species.

site preparation. 

In general, high-intensity site preparation hastens development of the forest, and in so doing diminishes wildlife habitat. pAn ecological study comparing high intensity with low intensity site preparation demonstrated that, after nine years, low-intensity sites had a well-developed grass/palmetto understory and little shrub growth. The understory supported a large number of insects, which in turn supported a variety of insect-feeding animals, including opossums, armadillos, and shrews. In comparison, high-intensity site preparation had a greater degree of crown closure and a more developed shrub layer. This greatly reduced the amount of ground forage, and the site supported some animals that prefer more open ground level conditions, namely rabbits, bobwhites, and cotton rats.

Although site preparation techniques such as cultivation and fertilization may reduce the total understory, scientists have found that the proportion of desirable understory forage plants is sometimes greatly increased. After 12 years, prepared sites provided better deer habitat than non-prepared sites. The scientists concluded that intensive pine culture can be compatible with maintaining deer habitat. Other site preparation techniques can help wildlife also. Burning in Florida flatwoods is often beneficial. Also, the piling of debris to form windrows provides food and cover for deer, bobwhites, and cottontails.

In general, when considering a variety of wildlife species, less intensive levels of site preparation are probably more favorable than more intensive levels. However, certain game species, particularly the white-tailed deer, are helped in some cases by higher intensity site preparation.

Controlled use of fire in Florida flatwoods is a valuable management tool. Pine forestlands are burned to accomplish at least one of the following goals: 1) to dispose of debris from timber harvesting operations and to prepare the site for planting, 2) to reduce understory litter to prevent wildfires, 3) to control insect pests or diseases, 4) to increase the quantity and quality of edible plants for cattle and/or wildlife, 5) to recycle nutrients bound up in plant litter and debris back into the soil, and 6) to alter or enhance the structural aspects of wildlife habitats.

Native plants and animals of Florida flatwoods have evolved in the presence of frequent burning in many pine forest types. Shrubs such as saw palmetto, pawpaw, yaupon, sweetleaf, sumac, and blackberry all respond vigorously to periodic burning. Other species are limited by fire. Exclusion of fire for the first 10 or 15 years in pine plantations may, therefore, have drastic effects on the development of the forest as an ecosystem.

Prescribed Burning

Burning schedules are extremely important in the development of habitat conditions favorable for various wildlife species. A one- to two-year burning schedule keeps the understory open and creates habitat favorable for bobwhites. A three- to five-year burning schedule allows for development of browse and cover plants, thereby favoring deer and turkeys. A three- to five-year schedule also allows the accumulation of sufficient fuel to support the next prescribed burn, and is most compatible with timber production.

prescribed burn. 

When planning a prescribed burn, the advice of a professional forester or technician should be sought. A burn that is planned and carried out in a careful and knowledgeable manner can be a safe and effective management tool. Burns are often conducted in the winter shortly after a rain, although there is some evidence that summer burns were historically more common and may be better for wildlife due to the "patchy" nature of these burns. A day with a slow, steady wind is desirable. Keeping the blocks of land to be burned relatively small will allow you to stop the burn any time that conditions become dangerous. The areas to be burned should be surrounded by natural barriers or plowed fire breaks.

A burn is always begun by setting the fire on the downwind side of the site so that the fire will burn slowly back into the wind. Such a fire is considered safe provided the wind does not change direction. The upper surface layer of pine needles and grass will fuel the fire, but the lower organic layer should be moist enough to resist burning. A slow, steady wind will help to spread the heat before it rises into the tree crowns, and will facilitate a backfire. After burning, always make follow-up observations to prevent flare-ups from smoldering stumps or logs.

Forest Fertilization

Florida pine flatwoods are often lacking in necessary nutrients, especially phosphorus. Fertilization , therefore, has a major effect upon the growth of pines and influences the quality of flatwoods habitats for wildlife. Soils that are lacking in phosphorus produce poor quality deer browse that cannot support large populations. The body weights and general condition of deer can actually be predicted by knowing the phosphorus levels in the soil.

Fertilization. 

If phosphorus is applied to the forest before crown closure or if thinning is accompanied by fertilization, then understory plants of superior quality result in enhanced forage for deer. Sometimes deer damage to pines in young plantations can become a major concern. One suggestion is to create an alternative food source by fertilizing native plants a short distance away from the affected stand. In general, it seems that most wildlife species will benefit from forest stand fertilization, especially when it is done early in the stand's development or later along with thinning operations.

Thinning is the process of removing lesser quality trees from the forest. Thinning in pine stands reduces light competition and improves both the form and growth of trees left standing. The first thinnings usually produce pulpwood that is used in the manufacture of paper products. Later thinnings will produce 8-inch diameter at breast height (DBH) pines, or greater diameter chip-and-saw trees that will make chips and boards from the same tree. Prices for chip-and-saw trees may be double those for pulpwood.

Thinning (TSI)

The development of understory vegetation, without thinning and burning, is inhibited due to the lack of light penetration through the pine crowns, the root competition for water and nutrients, and the heavy accumulations of organic litter that ties up nutrients. Thinning opens up the pine canopy of plantations, which allows understory and midstory vegetation development that is extremely important for many wildlife species. In general, thinning as early in plantation development and as often as possible is favorable both for wildlife and for forest health and productivity.

thinning. 

CONCLUSIONS

Managing forested land can be a profitable and rewarding experience. It can provide a satisfying livelihood for some, or a pleasurable pastime for others. But managing a multiple-use resource always involves trade-offs when making decisions. By defining priorities and making plans based upon sound knowledge and experience, then intelligent, long-term decisions can be made. It is as difficult to generalize about management of all wildlife, just as it is to generalize about all combinations of forest management. Some forest management practices are more favorable than others for some wildlife species.

The key to management for favoring many wildlife species is in trying to maintain or enhance the variety of vegetation (wildlife habitats) found in an area. Generally, the greater the variety, the greater the use by wildlife. This publication provided some guidelines for managing pine forests in Florida flatwoods to favor wildlife. If you desire additional information on some of these topics, contact your County Cooperative Extension or Division of Forestry offices.

Tables

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.

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