Science, Vol.269, No.5222, 350-354, 1995
Restoring Value to the Worlds Degraded Lands
Roughly 43 percent of Earth’s terrestrial vegetated surface has diminished capacity to supply benefits to humanity because of recent, direct impacts of land use. This represents an similar to 10 percent reduction in potential direct instrumental value (PDIV), defined as the potential to yield direct benefits such as agricultural, forestry, industrial, and medicinal products. if present trends continue, the global loss of PDIV could reach similar to 20 percent by 2020. From a biophysical perspective, recovery of similar to 5 percent of PDIV is feasible over the next 25 years. Capitalizing on natural recovery mechanisms is urgently needed to prevent further irreversible degradation and to retain the multiple values of productive land.
Keywords:TROPICAL DEFORESTATION;SUCCESSION;ATMOSPHERE;AMAZONIA;KRAKATAU;FORESTS;DESERTIFICATION;COLONIZATION;ECOSYSTEMS;PATTERNS