干旱地区山地荒漠草原阴坡植物群落空间异质性

在样线调查基础上 ,以 Shannon- Wiener指数 ,群落盖度 ,DCA排序轴为区域化随机变量 ,应用半方差、分形分析等方法 ,对干旱地区山坡植物群落空间异质性进行了研究。结果表明 ,在整个山坡尺度上植被格局的空间异质性不大 ,小尺度上植被格局的空间异质性较大 ,尺度依赖性较强 ,不同群落类型的空间格局不同 ,随尺度变化的规律也不一样。严重放牧干扰强烈影响干旱山地植物群落的空间格局 ,生境中的牧道格局 ,斑块格局使山坡植物群落多样性空间异质性更加复杂 ,牧道效应是导致群落空间格局周期性振荡的重要因子。去势对应分析 (DCA)排序第一轴特征值体现了综合生态因子对群落格局作用的结果 ,DCA第二轴半方差变化包含了大量信息 ,其变化具有周期性。群落多样性空间格局强烈影响着干旱山地生态系统的各种生态学过程 ,这些作用机制有待进一步研究

Spatial heterogeneity of the north slope's plant communities in the mountain desert grassland of the arid region

The spatial heterogeneity of ecology lies in its ubiquity as a feature of ecosystem. It has drawn more attentions in the research of ecosystem processes in recent years. The arid mountainous regions of northwest parts of China are considered as the sensitive ecological zones to affect environment of China. However, the ecosystem functions of those areas have been adversely affected by some reasonless activities of mankind, such as overgrazing, mining and digging up the roots of herbs etc. Therefore, a bette...