科尔沁沙地景观空间格局及其生态环境效应分析

基于2000年的土地利用图形数据，选用生态意义较明确的景观特征指数，从区域和旗县2个尺度定量分析了科尔沁沙地的景观空间格局，并揭示了景观格局对区域生态环境的影响。结果表明：（1）草地景观是科尔沁沙地面积最大、分布最广、连续性最强的基质景观，其面积比例为47．6％，斑块个数比例为29．8％，平均斑块面积高达3．25km^2／个，斑块分离度仅为0．40；耕地和林地景观的面积比例也较大，分别为26．3％和10．2％，流动沙地和盐碱地的面积比例较小，分别为5．8％和3．1％。（2）位于西辽河下游干流或支流沿岸冲积平原上的旗、县，其区域景观格局基本呈现出耕地与草地、流动沙地景观类型镶嵌分布的特征。（3）相关分析发现，研究区景观斑块类型的平均斑块面积大小与生态环境指数间呈显著正相关，而景观破碎化指数与生态环境指数间呈显著负相关。

Analysis of Landscape Spatial Pattern and Its Eco-Environmental Effect in Horqin Sandy Land

Basing on the sketch date of land use in the year of 2000,using the more explicit landscape metrics we quantify and analyze the landscape spatial pattern in Horqin sandy land and in term of regions and banners to reflect the affect of landscape pattern on regional eco-environmental.The result shows:(1)Grassland landscape is the biggest in area,the most extensive in distribution,and the strongest in consecution substrate landscape in Horqin sandy land.Its area proportion is 47.6%,patch number proportion 29.8%,average patch area higher than 3.25 km2/per,patch dispersion index only 0.40.The area proportion of farmland and woodland is also great by 26.3% and 10.2%.The area proportion of mobile sandland which is 5.8% and alkaline land which is 3.1% is small.(2)The Banners,counties on the alluvial plain on both side of the downstream and bayou of western Liaohe River.The landscape pattern on the regional reflects the feature of mosaic of substrate landscapes of farmland,mobile sandland and grassland.(3)The correlation analysis shows,there is a remarkable positive correlation between the eco-environmental index and the average patch area of the landscape,and that there is a negative correlation between the fragmentation index of landscape and the eco-environmental index.