Abstract: Based on the GIS/RS techniques and the methods of landscape ecology and Logistic regression, this paper analyzed the landscape change and its driving forces in Hun-Tai river basin from 1988 to 2004. The main landscape types in the river basin were forestland, shrub land, dry land, and rice field, but the land scape pattern changed greatly during the study period. The dry land and rice field decreased, forestland, water area, and rural and urban areas increased, while shrub land changed slightly. At landscape level, the landscape heterogeneity and fragmentation increased, while the patch spatial connectedness and landscape dominance decreased. The driving forces of the landscape change varied widely, among which, socio-economic forces played an important role, but the effect of natural forces could not be ignored.

Key words: Marine bacteria, Alexandrium tamarense, Paralytic shellfish poison