Abstract: This study analyzed how the landscape pattern dynamic changes affected the ecological service values in grasslands and arable lands in the central arid zone of Ningxia since 1990s. Hongsibu area,Tongxin county,Haiyuan county and Yanchi county were selected as the study areas and TM images from 1989, 1999, 2006 and 2011 were selected as the main data sources. Remote sensing, GIS and landscape ecology research methods were adopted. The results showed that the areas of the grasslands and the irrigated lands significantly increased in the above mentioned regions, which played an important role in environment optimization. The land use pattern has been greatly changed due to the human activities. The degree of fragmentation and spatial heterogeneity obviously increased, which resulted in ecological environment degradation. Since the beginning of the 21st century, the adoption of the environmental polices such as the implementation of the returning grain plots to forest or grassland, grazing prohibition, water conservation measures and ecological migration engineering improved the quality of the ecological environment and the structure of the land use. Overall, the better the ecological environment, the higher the ecological service value. The ecosystem service value in certain degree reflected the quality of an ecological environment. The results of this study provided theoretical and practical knowledges to the land use policies and the ecological environment optimization.

Key words: landscape pattern, dynamic changes, ecosystem service value, central arid zone of Ningxia