Silviculture and Management of Southern Pine Plantations
In the 1950s, vast acreages of cutover forest land and degraded agricultural land existed in the South. Less than 2 million acres of southern pine plantations existed at that time. By the end of the 20th century, there were 32 million acres of southern pine plantations in the Southern United States, and this region is now the woodbasket of the world. The success story that is southern pine forestry was facilitated by the application of research results generated through cooperative work of the U.S. Department of Agriculture Forest Service, southern forestry schools, State forestry agencies, and forest industry. This chapter reviews the contributions of applied silvicultural research in land classification, tree improvement, nursery management, site preparation, weed control, and fertilization to plantation forestry in the South. These practices significantly increased productivity of southern pine plantations. Plantations established in the 1950s and 1960s that produced < 90 cubic feet per acre per year have been replaced by plantations established in the 1990s that are producing > 400 cubic feet per acre per year. Southern pine plantations are currently among the most intensively managed forests in the world. Growth of plantations managed using modern, integrated, site-specific silvicultural regimes rivals that of plantations of fast-growing nonnative species in the Southern Hemisphere. Additional gains in productivity are likely as clonal forestry is implemented in the South. Advances in forest biotechnology will significantly increase growth and quality of future plantations. It appears likely that the South will remain one of the major wood-producing regions of the world.
Management practices in southern pine plantations have undergone a dramatic evolution over the last 50 years. By applying research results to operational plantations, foresters have more than doubled the productivity of operational southern pine plantations over this period. For example, older management practices that produced plantations with growth rates of < 90 cubic feet per acre per year have been replaced by new practices that create stands that are currently producing 400 cubic feet per acre per year on some sites. Pine plantations in the South are among the most intensively managed forests in the world (Schultz 1997). Site-specific, integrated management regimes that incorporate the genetic gains available from tree improvement along with silvicultural practices that optimize resource availability throughout the rotation are now the norm. Growth rates in many pine plantations in the South are now approaching those in the Southern Hemisphere. Additional gains in productivity are likely as management regimes are refined further. In the near term, implementation of clonal forestry holds the greatest promise to dramatically increase productivity in southern pine plantations. As a result, the South is likely to remain the woodbasket of the United States for the foreseeable future.
Encyclopedia ID: p1082
