摘要
定量描述鱼类分布的空间变异 ,有利于从生态学意义上理解其空间分布及其与环境的关系 .本文利用地理信息系统将东海区中上层鱼类资源密度空间化 ,运用空间自相关指数Gearyc和变异函数理论分析其空间自相关和空间变异 .东海区中上层鱼类资源空间分布平均场的Gearyc指数为 0 .2 5 ,各向同性随机变异占总变异的 19.1% ,表明其空间分布具有较高的自相关特性 .空间分布上各向变异不一致 ,其中4 5°和 135°方向上变异曲线斜率急剧变化 ,表明这两个方向上存在重要的环境动力过程 .各年份平均资源密度与相关变异 (C)正相关 ,而与随机变异 (C0 )不存在相关 ,表明年际密度变化主要由空间自相关引起 .变异曲线分维数 (D)与密度呈负相关 。
Quantitative description of spatial heterogeneity can help the understanding of the distribution of fishery resources and its relationship with the environment from ecological view. Based on geographic information system, the Geary index for the density distribution of pelagic fish was calculated, and the semivariograms were drawn. The Geary value c was 0.25 and Co/ (Co+C) was 19.1%, indicating that the distribution of the pelagic fish had a high spatial autocorrelation with anisotropy. The sharp slope of semivariogram in the directions of 45° and 135° meant that there existed important dynamic environmental processes in the two directions. The annual fluctuation of fishery resource density was caused by the spatial autocorrelation, because the density had a significantly positive correlation with value C, but no correlation with C 0. The fractal dimension D was negatively correlated with the density, meaning that the density increase was resulted from the increase of spatial fish centralizing.
出处
《应用生态学报》
CAS
CSCD
2003年第11期1971-1975,共5页
Chinese Journal of Applied Ecology
基金
国家"8 63"计划资助项目 (2 0 0 2AA63 940 0
2 0 0 1AA63 3 0 10 )
关键词
鱼类资源
地理信息系统
空间异质性
变异函数
空间自相关
Fishery resource, Geographic information system, Spatial heterogeneity, Semivariogram, Spatial autocorrelation
