REDUCING PRESSURE ON NATURAL FORESTS THROUGH HIGH-YIELD FORESTRY

High-yield forestry can make a valuable contribution to the conservation and sustained use of forest ecosystems. Despite the pressing reasons for conserving forest resources, population growth creates pressures for exploiting them. Unless needs for forest products, export credits, and local employment can be met by new devices, such as high-yield forestry, these pressures will be irresistible. Concentrating wood production on high-yield plantations increases flexibility in the use of forests and forest lands, making it possible to allocate native forest to parks and reserves. High-yield plantation managemnet implies the following: (1) choosing the appropriate species; (2) improving the composite genotype of the plantation trees; (3) optimizing the morphological and physiological condition of the trees prior to and at planting time; (4) improving the physical environment of the crop at all stages of development; (5) protecting the plantation from pests and catastrophic events; and (6) modifying the shapes, dimensions, and qualities of crop trees to enhance the utility and value of harvested timber. In addition to the advantages that plantations have demonstrated in the temperate zones, tropical plantations capture the benefits of a benign physiological environment, namely near-constant year-round temperature, and the absence of frost. Relative to the productivity of undisturbed or partially logged humid tropical forests, plantation growth rates represent 4-10-fold increases in volume production. Displacement of some proportion of shifting agriculture and natural forest management (or mismanagement) systems by high-yield forest plantations is desirable and biologically feasible. The ultimate key to both conservation and succesful tropical-forest management is population stability, a condition toward which integrated wood-processing facilities, supplied by a reliable plantation system, can make a major contribution. © 1990.