Variation in soil properties as a result of the conversion of the tropical rainforest to a monospecific plantation of teak, tectona grandis, was examined in Akure forest reserve in Southwestern Nigeria. Comparison was...Variation in soil properties as a result of the conversion of the tropical rainforest to a monospecific plantation of teak, tectona grandis, was examined in Akure forest reserve in Southwestern Nigeria. Comparison was made in the active rooting zone of 50 cm soil depth. It was discovered that there were no significant differences in the physical properties except in the value of organic matter content at the top 10 cm layer but chemical properties such as the pH and organic carbon changed significantly at the top 10 cm layer. Differences in other chemical properties, such as the available P, exchangeable cations K, Ca and Mg, the exchangeable acidity and the cation exchange capacity were minor. This showed that no nutrient was limiting or was likely to be limiting in the soil for subsequent short rotation of plantation development.展开更多
Cyclic climatic changes, as well as the press of anthropogenic impact, affect ecosystems of the river Argun basin. Specialization of basin management is industrial and agricultural. The main impact is connected with t...Cyclic climatic changes, as well as the press of anthropogenic impact, affect ecosystems of the river Argun basin. Specialization of basin management is industrial and agricultural. The main impact is connected with the development of mining companies （including the mining of ore and placer gold）, energy facilities, and the formation of reservoirs in the basin of rivers： the Argun -- the Hailar. As a result of natural and anthropogenic pressure, the limiting factor for ecosystem exploitation in this basin is water resources （water deficiency and its quality）.展开更多
文摘Variation in soil properties as a result of the conversion of the tropical rainforest to a monospecific plantation of teak, tectona grandis, was examined in Akure forest reserve in Southwestern Nigeria. Comparison was made in the active rooting zone of 50 cm soil depth. It was discovered that there were no significant differences in the physical properties except in the value of organic matter content at the top 10 cm layer but chemical properties such as the pH and organic carbon changed significantly at the top 10 cm layer. Differences in other chemical properties, such as the available P, exchangeable cations K, Ca and Mg, the exchangeable acidity and the cation exchange capacity were minor. This showed that no nutrient was limiting or was likely to be limiting in the soil for subsequent short rotation of plantation development.
基金National Natural Science Foundation of China(41271556)National Natural Science Foundation of China and Russian Foundation for Basic Research(414110106515-56-53037)
文摘Cyclic climatic changes, as well as the press of anthropogenic impact, affect ecosystems of the river Argun basin. Specialization of basin management is industrial and agricultural. The main impact is connected with the development of mining companies （including the mining of ore and placer gold）, energy facilities, and the formation of reservoirs in the basin of rivers： the Argun -- the Hailar. As a result of natural and anthropogenic pressure, the limiting factor for ecosystem exploitation in this basin is water resources （water deficiency and its quality）.
