非表示:
キーワード:
tropical wetlands; watershed management; flood plain
要旨:
Tropical wetlands assume important functions in the landscape and contribute considerably to the welfare of large parts of the human population, but they are seriously threatened because they are considered free resources of land and water. This review summarizes long-term environmental trends for tropical wetlands and predicts their future to the time horizon 2025. Many tropical countries do not have the economic strength, scientific and technological capacity, and/or administrative infrastructure to adequately react to the challenges of increasing population pressure and globalization of the economy with respect to the sustainable use of the resources. Furthermore, political instability and armed conflicts affect large areas in several tropical countries, hindering wetland research and management. Detailed wetland inventories are missing in most countries, as are plans for a sustainable management of wetlands in the context of a long-term integrated watershed management. Despite large regional variability, a continental ranking shows, in decreasing order of wetland integrity, South America, Africa, Australia and Asia, while efforts to mitigate human impacts on wetlands are largest and most advanced in Australia. Analysis of demographic, political, economic and ecological trends indicates fairly stable conditions for wetlands in tropical Australia, slight deterioration of the large wetland areas in tropical South America excepting the Magdalena and Cauca River flood plains where human population is larger, rapidly increasing pressure and destruction on many African and Central American wetlands and serious threats for the remaining wetlands in tropical Asia, by the year of 2025. Policy deficiencies, deficient planning concepts, limited information and awareness and institutional weakness are the main administrative reasons for wetland degradation and must be overcome to improve wetland management and protection in future. Intensification of international cooperation and assistance is considered of fundamental importance for most tropical countries to solve problems related to wetland research, protection and sustainable management.
