斑块尺度湿地植物群落多样性的维持能力

基于GIS技术和主成分分析方法，对1950、1967、1983和2000年挠力河流域湿地景观斑块特征与斑块内植物群落多样性之间的关系进行了研究.结果表明： 1950—2000年间，研究区湿地斑块平均面积逐渐减小，能够维持2种及2种以上植物群落的斑块数量逐渐减少，最小斑块面积为10.1 km²;湿地斑块面积与植物群落多样性指数和群落类型数均呈极显著正相关关系（P<0.01），湿地斑块面积越大，维持植物群落多样性的能力越强;随着湿地斑块面积的逐渐减小，斑块破碎化指数和分维数逐渐增大，形状指数和斑块内植物群落多样性指数逐渐减小;随着湿地斑块空间分离度的增大，斑块内植物群落多样性指数呈减小趋势;主成分分析结果显示，研究区湿地斑块面积大小是影响斑块内群落多样性的最重要因素，其次为斑块的破碎化程度和分离度.

Maintenance capacity of plant community diversity of wetlands in patch scale.

Based on GIS and principal component analysis method, this paper analyzed the relationships between the patch characteristics and the plant community diversity in the patches of wetlands in Naoli River Watershed in 1950, 1967, 1983 and 2000. The results showed that in 1950〖KG-*2〗-〖KG-*7〗2000, the average patch size of the wetlands and the number of the patches that had the capacity of maintaining more than two types of wetland plant community decreased dramatically, and the minimum patch size was 101 km2. Both the plant community diversity index and the number of plant community types had significant positive correlations with the patch size of the wetlands. The larger the patch size, the higher maintenance capacity of plant community diversity. With the decrease of patch size, the patch fragmentation index and patch fragmental dimension increased, while the patch shape index and the plant community diversity index in the patches decreased. With the increase of patch spatial separation, the plant community diversity index in the patches decreased. Principal component analysis indicated that patch size was the most important factor affecting the plant community diversity of wetlands, followed by patch fragmentation and separation.