庐山香果树毛竹混交林空间格局研究

Spatial distribution pattern in Emmenopterys henryi and Phyllostachys edulis mixed forest in Lushan Mountain

为了解庐山毛竹入侵对香果树的影响,采用Ripley’sK(t)函数分析香果树毛竹混交林群落空间分布格局和种间关联关系。结果表明:香果树幼树在较小的尺度上呈聚集分布,较大尺度上随机分布直至均匀分布;香果树成年树在较小的尺度上呈随机分布,较大尺度上聚集分布;毛竹在所有的研究尺度上为显著聚集分布,且随着尺度的增大,聚集强度增加。毛竹与香果树幼树在较小的尺度上没有明显关联性,在较大的尺度上呈显著负相关;毛竹与香果树成年树在一系列尺度上均表现为显著负相关。根据空间关联性分析结果,应从幼龄起对生长有香果树的森林群落进行必要的管理,伐除毛竹及一些影响较大的其它乔木树种,挖除地下竹鞭,为香果树提供良好的生长环境,进而恢复其种群的天然合理配置。否则,香果树这一珍贵的植物资源在庐山将有灭绝的危险。

In order to understand the effects of Phyllostachys edulis expansion on Emmenopterys henryi in Lushan Mountain, a typical plot of 50 m×50 m was surveyed and Ripley’s K（t） function was applied to diagnose spatial patterns and spatial associations between species pairs. Phyllostachys edulis saplings showed aggregated distributions at relatively smaller scales and tended to be randomly or regularly distribution at larger scales. Adult Emmenopterys henryi showed random distribution at smaller scales and aggregated distribution at larger scales. The spatial pattern of Phyllostachys edulis was aggregated distribution at all scales, the aggregation degree increased with the scales. No significant correlation was observed between Phyllostachys edulis and Emmenopterys henryi saplings at smaller scales, but there was generally a significantly negative correlation between them on the larger scales. There was significantly negative correlation between adult Emmenopterys henryi and Phyllostachys edulis at all scales. Population patterns and spatial association depended on spatial scales, individual sizes and so did their inter-specific. Necessary management should be taken to the forest communities where Emmenopterys henry grew. Harvesting bamboos including rhizome and some other larger trees would provide a good environment for Emmenopterys henryi and restore its nature and reasonable population configuration. Otherwise, Emmenopterys henryi as a rare and endangered species would be in danger of extinction in Lushan Mountain.