三江平原孤立湿地景观空间结构

受人类活动的影响,近几十年来三江平原大片连续湿地逐渐破碎化,形成了大量孤立湿地。湿地景观格局分析已成为湿地生态和全球变化研究领域的热点,因此以三江平原遥感影像为数据源,利用GIS技术和景观指数模型,在60m分析粒度下,对三江平原孤立湿地景观空间结构进行分析。结果表明:1研究区的中南部孤立湿地的斑块数量较多,而中东部孤立湿地的斑块面积较大,且孤立湿地斑块之间的邻近程度和连接度较高,三江、洪河自然保护区及研究区西部孤立湿地斑块的形状较复杂;2随着湿地斑块数量的递减,非孤立湿地在景观连接中起到的作用逐渐增加,孤立湿地在景观连接中起到的作用逐渐减小,但面积相对较大的孤立湿地斑块重要值一直处于较高水平,在景观连接中起着重要作用;3三江平原孤立湿地景观空间结构是地形地貌、农业开发活动、国家政策等因子综合作用的结果,应加强对孤立湿地的保护。

Analysis on the spatial structural of isolated wetland landscapes in the Sanjiang Plain

In the Sanjiang Plain of northeastern China, extensive amounts of continuous wetlands have been fragmented gradually over time as a result of human activities. This has led to the formation of a large number of isolated wetlands over the past few decades. Analyses on the spatial structural of isolated wetland landscapes has become a hot topic in the area of wetland ecology and global change. In this paper, we analyze the spatial structure of isolated wetland landscapes in the Sanjiang Plain. The analyses were based remote sensing images of the Sanjiang Plain taken in 2010, and the detailed landscape spatial structure of the isolated wetlands was created by using geographic information system (GIS) technology and a landscape model, under a resolution of 60 m. The results show that there are a number of isolated wetlands in the central-southern part of the plain, and the larger isolated wetlands are mainly distributed in the Middle East, at the same time, the adjacent degree and connection degree are higher between the isolated wetland patches, what''s more, the shapes of the isolated wetland patches are more complex in Sanjiang and Honghe nature reserves as well as the study area in the west. With the reduce number of the wetland patches, non isolated wetlands increase gradually and play a role in landscape connection, on the contrary, the isolated wetlands'' effect is gradually reduce, however, the isolated wetland patche value always in a higher level, and it also plays an important role in landscape connection. Overall, the landscape spatial structure of isolated wetlands in the Sanjiang Plain appears to be the result of comprehensive effects from the topography, agricultural development, national policy, and other factors.