基于景观斑块谱特征分析的湿地景观变化对丹顶鹤栖息地影响研究

Effects of Changes of Wetlands Landscape on Habitats of Red-Crowned Crane Based on Patch Charts in the Sanjiang Plain,China

选择三江平原东北部为研究区域，通过对1954—2005年6个时段景观图湿地斑块谱特征分析，结合野外丹顶鹤栖息地调查，揭示了湿地景观斑块化对丹顶鹤栖息地的影响。结果显示：①空间上，区域湿地景观以大斑块为优势地位，小斑块数量众多，总体斑块数量大；大斑块形状复杂且富有生态系统类型多样性，小斑块形状规则但异质性差；时间上，大斑块面积持续缩小，小斑块数量持续增加，景观破碎化过程明显；大斑块形状趋于复杂，内部异质性降低明显，景观多样性趋于简单化。②景观斑块化不仅导致丹顶鹤栖息地面积大量丧失，而且边缘效应和斑块异质性影响严重削弱了斑块维持栖息地的能力。③景观斑块谱特征决定了斑块资源的有效程度。在低度破碎化的景观中，斑块面积影响起主要作用，而在高度破碎化景观中，斑块形状和多样性影响更为突出。

The northeastern Sanjiang Plain was once a largest fresh water wetland distribution area in China and an important habitat for Red-crowned Crane as well. But, with several large-scale land reclamation activities taking place cantly. As a result, wetlands were in crowned Crane was sharply declined. changes in landscape scale. So, based in this region, the landscapes have been changed signifivery serious fragmented state, and the population of Red- This phenomenon seems to be clearly related to wetland on six periods of landscape patch chart analyses from 1954 to 2005 by GIS Techniques, and combined with field surveys on habitat factors for Red-crowned Crane, we explored the effects of wetland changes on habitats of Red-crowned Crane in the study area. We got conclusions as following ： （ 1 ） the landscape of wetlands was in spatial characterized as predominance of several larger sizes of patches, and with large amount of small size of patches ; the large size of patches not only have complex of shapes, but also were rich in diversity of ecosystem types, however, small size of patches have regular shapes but with poor heterogeneities. （2） The dynamic of landscape in temporal was characterized as larger size of patches continued to decline and small size of patches increase, which indicated the clear fragmentation process of landscape taking places in historical periods ; however, the shapes of larger size of patches going to be complicated with the heterogeneity of patches declined significantly and landscape diversity going to be simplified. （3） The fragmentation of wetlands in landscape not only resulted in large areas of habitat loss for Red-crowned Crane, but also brought significant effects of edge and heterogeneity in patch scale, which seriously weakened the maintains capacity of patch on habitats and population of Red-crowned Crane in the study area. （4） The characteristics of pat- ches determined the degree of resources availability. Patch size has main effects on habitats in the lower fragmented landscape, however, the effects of patch shape and diversity of ecosystem have more impacts on habitats in a higher fragmented landscape.