Abstract: 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.

Key words: Nutrient distribution, Eutrophication, East China Sea, Red tide