Longleaf pine forests provide habitat for many wildlife species, such as fox squirrels, wild turkeys and whitetail deer. Photo by Andrea De Stefano.

According to the Louisiana Department of Agriculture and Forestry, forestland covers about 48% (13.8 million acres) of Louisiana land. Most of the state’s forestland is privately owned (91%), 62% owned by non-industrial landowners, 29% owned by forest products industries, and the remaining 9% public owned.

Among private landowners, family forests — defined as tracts of forested areas of 10+ acres owned and managed by individuals or families — play an important role in forestry and natural resources management. Family forest owners have diverse management goals and practices for the forestland they own, including nonfinancial objectives such as family legacy, wildlife, aesthetics, conservation, hunting and recreation as indicated by several surveys.

A multiple-use approach in forest management involves decisions and practices that promote those goals and considers environmental (species composition, soil, climate, topography), social (aesthetics, recreation, laws and regulations), and economic factors (cost of management, land value, tree value, market trends). Often, multiple-use strategies cannot maximize one (e.g., economic) without foregoing other considerations. However, it is possible to maintain sustained yields of timber while enjoying the aesthetic qualities of forestland through hunting or other recreational uses.

One of the most common management interests for private landowners is to provide suitable wildlife habitat. It is important for landowners to understand the basic ecological principles that regulate the composition and density of a timber stand rather than define the perfect stand or type for wildlife. Let’s look at one important concept of forest ecology: diversity. The familiar term “biodiversity” is usually associated with the number of species, but in reality, diversity is a complex, multidimensional concept.

• Genetic diversity: The range of different inherited traits within a species that are critical for survival. These traits provide the resilience that allows a species to adapt to changing conditions.
• Species diversity: The variety (total number and evenness) of species found in a particular place. Species diversity is further divided into alpha diversity (within a localized habitat such as a longleaf pine stand), beta diversity (how species diversity varies across different habitats of spatial units within a larger geographical area) and gamma or regional diversity (representing the total species diversity within a broad geographical region).
• Functional diversity: The variety of morphological, physiological and phenological characteristics that influence growth, reproduction and survival within a community or ecosystem. It emphasizes the role of the species in ecosystems functioning (stability, resilience and services).

The concept of diversity can also be extended to the species’ spatial arrangement, food chains and webs, energy pathways and interactions. For wildlife habitats, horizontal and vertical diversity are two important components.

• Horizontal diversity: The arrangement of plant species, successional stance and amount of forest components along a horizontal plane.
• Vertical diversity: The presence/absence of vertical layers (ground layer, understory, midstory, upper canopy).

These layers provide a way to account for spatial diversity and also give an idea about food sources and shelter opportunities for wildlife species.

A good management approach starts with an inventory of the components of a forest ecosystem and their attributes. A very first classification of a forest habitat identifies abiotic (nonliving) and biotic (living) components. Biotic components include vegetation, animals and microorganisms, while abiotic components include topography, climate, water, light, atmosphere, soil and geology. For instance, you can think about the tree component (biotic) and its attributes such as size (diameter at breast height and height), age classes, density, basal area, volume and so on. On the other hand, topography’s attributes (abiotic) include elevation, slope and aspect.

Diversity changes over time, which shapes the forest as a response to other factors such as disturbance, following a consistent and predictable sequence called plant succession.

In the plainest scenario (primary succession), bare ground is colonized first by lichens, then by annual herbaceous plants, followed by perennial herbaceous plants and small shrubs. At some point, light seeded pioneer trees, such as pine species, will start to colonize the area forming a canopy layer. These pioneer species create the right conditions that allow more complex and slow-growing species to establish. Shade tolerant tree and shrub species (e.g., oak species) will start to colonize the understory, waiting until a disturbance event (think of a lightning strike) creates a gap, giving them the opportunity to grow and reach the canopy layer. At this point, a climax forest is reached — a forest community that is stable and has reached the maximum development in terms of structure and species composition. Nevertheless, other disturbance events can and will occur, altering this stable condition and allowing pioneer species present in the seed bank — seeds that are already on site or in the soil — to reestablish and start a new cycle (secondary succession).

Understanding the concept of diversity and diversity over time will allow landowners to predict and plan for the type of plant community desired for a particular forest management practice, including promoting wildlife habitat.

Primary plant succession starting with no plant life.

Secondary plant succession as consequence of a disturbance event (fire).