不同生境中刺萼龙葵空间点格局分析

Spatial point pattern analysis of Solanum rostratum Dunal in different habitats

【目的】掌握刺萼龙葵种群的分布格局,为刺萼龙葵的有效控制提供理论依据。【方法】采用点格局方法,运用Ripley’s L函数对不同生境(河滩、草原和荒地)中的刺萼龙葵种群进行点格局及不同植株类型间的关联性分析。【结果】3种生境中的刺萼龙葵不同植株大小类型数量排序均为大型植株>中型植株>小型植株,大型和中型植株以河滩生境最多,草原生境最少。3种生境中,刺萼龙葵在小尺度上均表现为聚集分布,在大尺度上表现为随机分布或均匀分布。在河滩生境中,仅中型植株表现出微弱的聚集性;而在草原生境和荒地生境中,在中小尺度上大型植株和中型植株均表现出聚集性,且大型植株相较于中型植株表现出更强的聚集性。在河滩生境中,仅中型植株与小型植株间在小尺度上表现出显著正相关性,大、中、小3种植株类型间随着尺度的增大,不断趋于无相关性或显著负相关;在草原生境和荒地生境的中小尺度内,大、中、小3种刺萼龙葵植株类型间均表现出一定的显著正相关性,随着尺度的增大,不断趋于无相关性或显著负相关。【结论】入侵植物刺萼龙葵的群落空间格局在不同资源环境条件下均呈现有利于种群扩散的分布特征,且不同株型间易形成互利的生态关系,是其成功入侵的主要驱动因素之一。

【Objective】In this study,the effects of spatial distribution pattern of Solanum rostratum Dunal population on the invasion process was taken as the focus of attention. The aim of this study was to providea better understanding of the theoretical basis for S. rostratum control.【Method】Point pattern analysis(PPA)was adoptedto examine spatial point pattern and the correlation among populations of S. rostratum in different habitats(beach,grassland and wasteland)using Ripley’s L function.【Result】For the three habitats,the number of S. rostratum seedlings in different types ranked as large plants>medium plants>small plants. The numbers of large and medium plants in beach habitat were the largest,and in grassland habitat was the smallest. Populations of S. rostratum in three habitats showed aggregation distribution on small scale,and random or uniform distribution on large scale. In beach habitats,only medium plants of S. rostratum showed slight aggregation,while large and medium plants showed aggregation on small scalein grassland and wasteland habitats,besides,the large plants showed stronger aggregation than the medium plants. In beach habitats,only the medium plants and the small plants showed positive correlation in the small scale range,and the large,medium and small plant types tended to show no correlation or negative correlation with the increase in the scale range. In grassland and wasteland habitats,there was a positive correlation among the three plant types of S. rostratum in the medium and small scale range,however,no correlation or negative correlation as the increase of the scale range.【Conclusion】The spatial pattern of invasive plant S. rostratum community in different resource and environment conditions show distribution characteristics conducive to population diffusion,and the mutually beneficial ecological relationship between different plant types is formed,these are the main driving factors for its successful invasion.