Geography of the Forest An Overview

Those born beyond the forests of the tall pines and broad-beamed hardwoods of the South must acquire a taste for the region, just as they would acclimate to its ribbon cane syrup, corn pone, and breakfast grits.

When entering the forest from the west, one passes from the wide, flat space of the prairies into rooms bounded by green and brown vertical walls. Light sifts from above through the tree canopies as long, bright shafts. Sleepy swamps, covered with vines, branches, roots, and buttressed butts of baldcypress and broadleaf species, seem to come alive upon their entry by the sojourner. Indeed, to encounter for the first time the tall pines and widespreading hardwoods may seem somewhat like an initial visit to the narrow streets of Manhattan—one sees the same amount of light. Someone from the plains might be claustrophobic; another from the city homesick for the concrete jungle. It is in this, the South's environment, that the forester endeavors to grow trees for humanity's use and enjoyment.

Foresters refer to the characteristics of any particular locale that determine which species grow there and how fast they grow as "site factors." The four factors—physiographic, climatic, edaphic (referring to the soil), and biotic—interact to form ecosystems. The interrelationships of living things to each other and to their environment, called ecological processes or relationships, depend on these factors.

Early explorers and pioneers entered the South's forests without much understanding of overall climatic patterns for the region. They knew even less of the hills and swamps to be encountered; and beyond the pigmentation of the soil, observation was of little value. The smell or feel of the soil provided some recognition of land productivity. Geographic concepts, however, were well developed by the time of the migrating lumbermen. Foresters later capitalized on that information in formulating management plans for the vast pineries and hardwood uplands and bottomlands.

Boundaries of the southern forest depend on the surveyor. Some limit the region to the principal range of the hard pines, 10 species growing on various sites between New Jersey and Texas. Others exclude the Appalachian Mountains with two additional hard pine species (pitch and table-mountain) and a variety of northern hardwoods and the near-boreal coniferous red spruce and Fraser fir. Still, an observer could choose to map as part of the southern forest the hardwood timber types of the Ozark Plateau in Missouri and the Post Oak Belt in Texas, both areas sometimes considered part of the Central Hardwoods Region. All of these peripheral zones are included for our purposes as a part of the southern forest. Their contiguousness, the continuity of settlement and development of the land, and the interrelationships of species' range and timber harvests suggest the propriety of this boundary.

The southern forest thus comprises the area east of the prairies of Texas and Oklahoma and south of the Missouri, Ohio, and Potomac rivers, plus a northern extension along the Atlantic coast to central New Jersey. It embraces the range of the commercial southern pines, the productive sites of the southern river bottoms, and extensive forests of upland hardwoods. In addition to these three broad forest cover types—the term categorizing the composition of vegetation in the forest —southern silviculturists classify many lesser ones. The most important of the minor types are red spruce and Fraser fir, eastern white pine, eastern hemlock, eastern redcedar, baldcypress (and its pondcypress variety), and Atlantic white-cedar. Each has its niche in a biome, patterns of occurrence for each

Figure 1.1 Physiography of the Southern Forest Region. (after N. Fenneman, 1938)1

being a matter of the previously named geographic factors—physiographic, climatic, edaphic, and biotic.

Physiographically, the southern forest includes the lower elevations and relief of the Coastal Plain bordering the Atlantic Ocean and the Gulf of Mexico, the irregular to mountainous slopes of the Appalachian provinces, the interior highlands of Arkansas and Missouri, and the interior low plateaus of Kentucky and Tennessee. Each of these components is further divided on the topographer's charts. The Piedmont of the Appalachians and the lower alluvial valley of the Mississippi River, dissecting the Coastal Plain of the Gulf of Mexico, are examples of subregions explicitly noted here because of their significance to forestry. The Florida peninsula of the Coastal Plain, the Blue Ridge Mountains, and the Ridge and Valley zones of the Appalachians are slightly less obviously associated with the occurrence of timber types.

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