关键词: 农业活动, 土壤全氮, 地统计学, 科尔沁沙地, 空间格局

Abstract: Ajoint survey on ecologial environmemt of Horqin steppe was carried out by both Shenyang Institute of Applied Ecology,Chinese Academy of Sciences and China Central Television in August,2003.The investigation showed that grassland is degrading seriously.Land reclamation in a large scale is one of main reason of grassland degradation and decrease of grassland area.According to the investigation,a major issue is the remarkable declination of water resources,including declination of river water, lake water and falling of the ground-water table.Investigation showed that the desertification area in Horqin steppe is decreasing.The established artificial vegetation is increasingly reforced and its effect is remarkable. At present,however,area covered with the sand dunes out of control is still very large,and to control this area is considered as a very hard work.

Key words: Agricultural activity, Soil total nitrogen, Geostatastics, Keerqin sandy land, Spatial pattern