科尔沁沙地景观结构特征对沙漠化过程的生态影响

采用方差分析(ANOVA)、相关分析和回归分析,从时间和空间2个尺度对科尔沁沙地景观结构特征对沙漠化的生态影响进行了研究.结果表明,任何单一景观结构对沙漠化的影响都不明显.多因子PCA分析表明,景观结构对沙漠化有明显作用,它是景观承载了自然和人为作用后的景观要素组合对沙漠化的二次作用,是自然与人为作用的结果反馈.在时间尺度上,第一和第二分量占总信息量的90.26%,说明在过去40年中景观结构对沙漠化的影响相对简单,只有一个峰值.在空间尺度上,第一和第二分量占总信息量的80.20%,景观结构对沙漠化的驱动作用相对复杂,有2个峰值.这表明景观结构特征对沙漠化的影响在空间尺度上要比时间尺度上更为复杂.

Ecological effects of landscape structure on desertification process of Keerqin sandy land

By the methods of ANOVA, correlative analysis and regression analysis, this paper studied the ecological effects of landscape structure on desertification process of a typical Keerqin sandy land at spatial and temporal scales. The results showed that any single factor of landscape structure indices had no remarkable impact on desertification (significant at 95%). Principal component analysis (PCA) on the landscape structure indices suggested that landscape structure played an important role in desertification, because it reflected the interaction between natural changes and human being's activities and was the feedback of the interaction. At temporal scale, the contribution rate of the first and second vectors reached 90.26% of total information. There was a single peak in desertification, which indicated that the influence of landscape structure was simple during the past four decades. At spatial scale, the contribution rate of the first and second vectors was up to 80.20%, and there were two peaks in desertification, which indicated that the influence of landscape structure was more complicated at spatial scale than at temporal scale.