西南生态脆弱区类型及其特征分析

对生态脆弱区涵义加以界定,并全面阐述和分析了生态脆弱区具有特征的和性质。根据西南地区各区域生态与环境脆弱特征，结合自然环境特征和人类活动特点，以胁迫源、胁迫因子的交互作用和胁迫过程为主导。确定西南生态脆弱区的类型有5种，即：中度胁迫中度生态脆弱区、重度胁迫高度生态脆弱区、低度胁迫高度生态脆弱区、重度胁迫中度生态脆弱区、中度胁迫高度生态脆弱区。

CHARACTERIZATION OF FRAGILE ECO-REGIONS IN SOUTHWESTERN CHINA

As an eco-region with high fragility,the southwestern China is of importance for sustainable development.Fragile eco-region is defined as the continuous region,with interactions of human activity and natural factors,in which the capability against disturbance and restoration in eco-environmental system is low.Meanwhile,the adverse evolution can not be effectively controlled under current economical and technical conditions.The main features of fragile eco-region are intersections of stress,diversity of stress sources and stress processes,dimensions,high sensitivity,and heterogeneity of inner units as well as complexity of scaling etc.Based on vulnerably ecological and environmental features of regions integrated with physical conditions and characteristics of human activity,five types of fragile eco-regions had been divided in southwestern China depending mainly on sources,mutuality and processes of stresses,which were moderate stress and moderately fragile eco-region,strong stress and highly fragile eco-region,low stress and highly fragile eco-region,strong stress and moderate fragile eco-region,and moderate stress and highly fragile eco-region.