中文摘要：

北方农牧交错带地理位置特殊,脆弱性、敏感性是其主要特点。气候变化背景下我国北方农牧交错带范围也发生了相应变化。文中参考已有的界限指标,结合北方农牧交错带及其周边地区（11个省、自治区及直辖市）208个站点1961-2010年的降水资料,确定新的界限指标划定北方农牧交错带的边界,并讨论其界限移动情况。经分析,北方农牧交错带大部分地区降水量呈减少趋势,气候变化对东部降水量影响较为明显,农牧交错带范围向东南方向移动,且南界移动幅度大于北界;北部西界向西移动约2个经度;同时我国北方农牧交错带范围增加约3.5×10^4Km^2,这一变化趋势与实际土地利用模式下农牧交错带移动情况相反,因此当前农牧交错带地区的土地利用方式不利于该地区生态环境的可持续发展,使该地区生态环境问题更加严重。

英文摘要：

Nowadays,climate change is a heated topic.Geographical position of farming pasture ecotone is very special.Vulnerability and sensitivity are the main features of this zone.Fluctuations of the climate change have a very important effect on the boundary shift of the transition zone.Therefore,the discussion on the impact of climate change on boundary shift of farming pasture ecotone in northern China has its realistic significance to the land-use.A new boundary index was introduced in the study.Based on boundary indices discussed before and the data of precipitation（from year 1961 to 2010,208 sites,eleven provinces）,the range of this ecotone in Northern China was mapped.Results showed annual precipitation in most region had generally increased,the impact of climate change was more significant in east,the boundary of farming pasture ecotone moved toward southeast due to climate change and the southern boundary moved more obviously than the northern boundary.Besides,western boundary moved with approximately 2 degree of longitude to west,and the whole area of the ecotone increased about 3.5×10^4km^2.The current land use is not appropriate for ecological environment and sustainable development in this area,which made the ecosystem environmental more serious.