保安湖—湖湾大型水生植物群落格局的研究

STUDIES ON MACROPHYTES COMMUNITY PATTERN IN A BAY OF BAOAN LAKE, HUBEI

用地质统计学中的半方差和双对数半方差图对保安湖—湖湾(黄风口)的大型水生植物群落格局进行了研究，在不同的尺度上对群落及其主要组成种类的空间异质性进行了定量的描述。结果表明：保安湖黄风口大型水生植物群落的双对数半方差图存在线性区域，群落具有分形特征(自相似性)。在不同的尺度下，群落和各组成种类空间格局具有不同的分形维数值，异质性程度存在差异。但其异质性程度不高，建议进行群落调查时，样方尺度应取520m；单一种群调查时的样方尺度取380m。

In this poper the authors use the semivariance and the log-log semivariograms of Geostatistic to study the macrophytes community pattern in a bay (Huangfengkou region) of Baoan Lake. The spatial heterogeneity of the community and the species were quantitatively described at different scales by carrying out an investigation on lengthwise transect and transverse transect. The result showed that the spatial pattern of the community and the species had different fractal dimension values on different scales (variable h values). The fractal dimension values of those dominant macrophyte species to different h values are all greater than 1.5 and smaller than 2. On a scale of 400m, the fractal dimension on lengthwise transect was 1.8635, and it was 1.8220 on transverse transect. This indicated that the difference of spatial heterogeneity existed between two macrophyte communities, but their degrees were not high. The fractal dimension on lengthwise transect is smaller than that on transverse transect on same scale, which indicated that spatial heterogeneity on lengthwise transect is more complex than that on transverse transect. Because the macrophyte community showed a comparative high homogeneity on its pattern, the right scale should be about 520 meters when we carry out the community investigation, and the right scale for population sampling showd about 380 meters.