Abstract: The farming-pasturing ecotone in western Jilin Province and eastern Inner Mongolia is a transitional area of sub-humid and semi-arid climate, where natural grassland was severely degraded and showed saline-alkalization and desertification.Anthropogenic activity was the main cause of the grassland degradation, and larger population pressure and irrational land use were the dominant factors that accelerated this degradation.The management options for the degradation would be the carrying-out of ecosystem health diagnosis, protection of health grassland, restoration and reconstruction of damaged grassland, and establishment of scientific management system.

Key words: Tobacco variety, Predatory arthropod community, Structure and dynamics