玄武湖菹草种群空间格局分析及其环境效应

Analysis of spatial pattern of Potamogeton crispus population in Xuanwu Lake and ecological impact

大型水生植物的分布格局与空间尺度有着密切关系,传统的分析方法只能分析一种尺度下的格局。引入点格局分析,以种群空间分布坐标点图为基础,分析各种尺度下的种群格局。运用点格局分析对玄武湖菹草种群的空间分布格局进行研究,并结合N、P等水质指标探讨其环境效应。结果表明,玄武湖菹草种群分布集群特征明显,且在尺度232-344m内聚集最为明显。从水质监测结果看,菹草种群有利于改善水体环境,无种群区的TN、TP和NO3-N浓度明显高于有种群区;溶解氧（DO）则表现为有种群区高于无种群区。菹草在空间分布上的明显规律性,会进一步导致水质参数的空间异质性。

Based on spatial point pattern, here we employed the technique of point pattern analysis to study the spatial pattern of Potamogeton crispus population in Lake Xuanwu. The results showed that the population was aggregated distribution and highly aggregated in the scale from 232 m to 344 m. Furthermore, the distribution pattern of Potamogeton crispus improved the water qual- ity. The concentrations of N and P in non-macrophytes regions were higher than that in Potamogeton crispus distribution regions, but the DO in Potamogeton crispus distribution regions was higher than that in non-macrophytes regions. The results indicated the space distribution pattern of the population of Potamogeton crispus would lead to spatial variability of water quality.