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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.