元谋干热河谷区森林消长与生态环境变化研究

在元谋干热河谷区，森林覆盖率1950年为12．8％、1973年为6．3％、1985年降至5．2％、1993年升至5．8％。而人类的社会、经济活动，是导致森林面积消长的主要原因。森林面积增减，是生态环境向良性或恶性方向转变的关键所在，针对森林减少和生态环境恶化的原因提出了恢复森林植被改善生态环境的对策。

Studies on the Increase and Decrease of Forest Area and Eco- environmental Change in Yuanmou Dry-hot Valley

In Yuanmou dry-hot valley, the forest cover rate is respectively 12.8% in 1950(In the early 1950s, above 2 000 m of the altitude in Liangshan area, there distributed Pinus yunnanensis forest, the forest cover rate reached 60%～70%. Between 1 500～2 000 m,still distributed tract Pinus yunnanensis forest.), 6.3% in 1973 (Because of the serious destruction during the periods of the “Great Leap” and “Cultural Revolution”, the forest area reduced greatly), 5.2% in 1985 (After 1978,because of the need of economic development, the forest was felled again) and 5.8% in 1993 (After 1985, energetically plant trees, the forest cover rate increased slightly). The human socio-economic activity (felled trees and plant trees) is the main cause of increase and decrease of forest area. The increase and the decrease of the forest area is the key of the eco-environment changes to good or bad condition (The decrease of forest area caused eco-environment worse. The drought and flood are gradually serious and the land desertification developed). Against forest decrease and eco-environment deterioration some countermeasures have been proposed to recover forest vegetation and improve eco-environment, i.e, strengthen young trees management and tending, close hills to facilitate afforestation and change slope cultivated land to afforestation; formulate favourable policy; rationally dispose tree species; use water-saving technique in afforestation .