ECOLOGICAL CONDITION AND ECOLOGICAL CONSTRUCTION IN DRY-HOT VALLEY OF YUNNAN PROVINCE
OuXiaokun(Institule of Ecology and Ceobotany,Yunnan University,Kunming,650091)
Dry-hot valleys represent one of the geological landscape units existing along thedrainage area of the rivers in southeast China, mainly scattered over the upper reaches ofthe Yangtze River.The ecological condition of the dry-hot vaIley is different from the sur-rounding areas. It is rich in sunshine and heat and poor in moigture content.This is theclimate characteristics of a dry-hot valley. The coverage rate of the forest and other vege-tation in dry-hot areas is very low;but the plant species, especially some useful species arein plenty because of the rich heat and sunshine. These areas lre also rich in mineral re-sources. The development of these areas has a long history and is more advanced in com-parison with other areas of Yunnan Province. To strengthen the ecological construction isvery important to the sustainable development of these areas and that will influence thelower reaches of the rivers,but ecological construction will be successful only when it isconnected with economic and social developrnent of the valley area.