人类活动干扰下希拉穆仁草原景观格局的演变

Evolution of Landscape Type in Xilamuren Grassland under the Disturbance of Human Activities

自2002年希拉穆仁草原经济结构调整后,天然牧草地的人为干扰持续增强,对草场的破坏程度也逐年增高,为了量化分析希拉穆仁草原在高强度人为干扰下的景观变化情况,本研究选取经济发展较慢的早年至近年的影像数据进行景观格局分析。年份选取为1999年、2002年、2005年、2007年、2011年、2014年和2017年,影像底图选用TM影像。解译选取年份影像资料,进行景观格局分析。结果表明:希拉穆仁草原在1999年—2017年景观破碎化程度呈增长趋势,并且程度加重,天然牧草地受分割严重。虽然草场面积减小仅18.52 km^(2),但斑块数增长了207.95%。旅游业发展的附属建筑居民点、旅游点和建设用地分别增长195.65%、6833.33%和141.48%。旅游区的面积更是从之前的0.12 km^(2)增长到8.19 km^(2),增长了68.25倍,呈持续增长,近年来成规模的旅游区增长速度加快。相关景观破碎化指数也随旅游业的发展而变化,整体景观斑块数从开始的151块增长到465块,最大斑块占比由63.04%减少到16.33%,平均斑块面积减少了67.47%,边缘密度指数增加109.25%,形状指数增加92.27%。对天然牧草地影响最大的干扰因素是旅游业,由旅游业发展的交通道路将原天然牧草地进行分割,导致牧草地的岛屿化加剧,且天然牧草地的破碎程度与旅游发展成正相关。

Since the adjustment of the economic structure of Xilamuren grassland in 2002,the human disturbance intensity of natural pasture has continued to increase,and the damage degree to the grassland has also increased year by year.In order to quantitatively analyze the landscape changes of Xilamuren grassland under high-intensity human disturbance,the image data from the early years with weak economic development to recent years were selected.The selected years were 1999,2002,2005,2007,2011,2014,and 2017.TM images were selected for the image base map,the image data of the selected years were interpreted to analyze the landscape pattern.The results showed that the landscape fragmentation degree of the grassland increased year by year from 1999 to2017,and the degree was deeper and deeper.The natural grassland was seriously fragmented.Although the grassland area decreased by only 18.52 km^(2),the number of patches increased by 207.95%.Ancillary building settlements,tourist spots,and construction land developed by tourism increased by 195.65%,6833.33%,and 141.48%,respectively.The tourist areas increased from 0.12 km^(2)to 8.19 km^(2),an increase of 68.25 times.The growth trend was sustained,and the growth rate of large-scale tourist areas had accelerated in recent years.The related landscape fragmentation index also changed with the development of tourism.The total number of landscape patches increased from 151 to 465.The proportion of the largest patches decreased from 63.04%to16.33%.The average patch area decreased by 67.47%,the marginal density index increased by 109.25%,and the shape index increased by 92.27%.The most influential factor affecting the natural pastures was the tourism.The original natural grassland was segmented by the traffic road developed by the tourism,and the fragmentation degree of natural grassland was positively correlated with the development of tourism.