土地覆盖变化和景观格局变化是研究生态环境变化及野生动物生境格局变化的重要基础。本研究基于内蒙古高格斯台罕乌拉国家级自然保护区1995、2004和2014年7月份3期landsat TM系列数据,运用RS、GIS技术及景观生态学的方法,系统分析了该区1995~2014年土地覆盖与景观格局变化,定量分析了土地覆盖类型变化度、斑块面积指数、斑块形状指数、边缘密度指数以及多样性指数等指标。研究结果表明:土地覆盖类型主要为草地、林地和灌丛半灌丛,约占保护区总面积的80%~90%;其中1995~2014年草地面积减少245.74 km2,林地增加99.73 km2,灌丛半灌木丛减少4.38 km2;从景观格局来看,1995~2014年间,斑块数量、斑块密度、平均形状指数均有较大波动,均为先增加后减少;而聚集度先变小后又增大;Shannon’s多样性指数逐渐递增,最大斑块指数逐渐减小。说明1995~2004年,景观趋于丰富和复杂化,2004年以后,破碎化程度减小并趋于稳定。该研究结果表明随保护区级别晋升,管护力度加大,保护区环境得到改善,但仍然面临土地退化的严重挑战。
Land coverage and landscape pattern changes are the important basis of the study in the change of ecological environment and wildlife habitat pattern. In our study, we got the three phases dataset of lands at TM at summer in July 1995, 2004 and 2014 in Gaogesitai-Hanwula national nature reserve, Inner Mongolia, and used techniques of remote sensing (RS), geographic information systems (GIS) and landscape pattern analysis method to systematically analyze the land coverage and landscape pattern change from 1995 to 2014, and quantificationally analyze land cover types change degrees, patch area index, patch shape index, edge density index and diversity index. Our results showed the grassland, woodland, brush and half shrubs were the main land coverage type. They occupied 80% - 90% of the total area. From 1995 to 2014, grassland decreased by 245.74 km2, forest land increased by 99.73 km2 and brush and half shrubs decreased by 4.38 km2. From 1995 to 2014 by the landscape pattern, patch number, patch density and mean shape index showed great fluctuations (increased firstly and then decreased quickly);the degree of aggregation firstly decreased and then increased;Shannon’s diversity indices gradually increased;and the largest patch index gradually decreased. It showed the landscape tended to be more abundant and complex from 1995 to 2004, and the degree of fragmentation was decreasing and tending to be stable. Our results also showed as the promotion of the level and the improvement of protection for the nature reserve, the environment of nature reserve was improved. However, it still faced the enormous challenge due to the land degradation.
International Journal of Ecology