水盾草入侵沉水植物群落主要种群生态位和种间联结研究

研究了水生外来植物水盾草(Cabomba carolimana)入侵沉水植物群落的不同种群生态位特征和种间联结性.选择了其扩散区域内的24个样地进行群落学调查,测定了群落中13个种群的生态位宽度、生态位重叠、多物种间总体关联性及成对物种间联结性,结果表明:①水盾草入侵沉水植物群落13个种群中,水盾草的生态位宽度最大,金鱼藻(Ceratophyllum demersum)、黑藻(Hydrilla verticillata)和苦草(Vallisneria natans)次之.②水盾草与金鱼藻、黑藻、苦草和黄花狸藻(Utricularia aurea)间生态位重叠较大,与其他物种间的生态位重叠较小.③水盾草和金鱼藻、苦草、黑藻之间具有一定的正联结,而与其他物种间的联结性不显著,基本上趋于独立出现.由此可见,水盾草在中国急剧扩散,对常见的乡土种有很大的负面影响,导致群落物种多样性下降,应加强防控研究.

Studies on niche characteristics and interspecific association of main populations in submerged communities invaded by Cabomba caroliniana

The niche characteristics and interspecific association of populations in submerged communities invaded by Cabomba caroliniana were studied.24 communities have been carried out and the niche breadths,niche overlaps,multi-interspecies association,and pair-interspecies association of 13 populations are obtained on the investigation.The results showed that:(i) Among the 13 populations,the niche breadth of C.caroliniana is the biggest,and Ceratophyllum demersum,Hydrilla verticillat,and Vallisneria natans is minor.(ii) C.caroliniana has greater niche overlaps with C.demersum,H.verticillata,V.natans,and Utricularia aurea,and those between C.caroliniana and other populations are smaller.(iii) C.caroliniana has positive association with C.demersum,V.natans and H.verticillata,and association with other populations is not significant that they occur independently.It can be seen that the rapid invasion of C. caroliniana has great negative effects to familiar native species,and it can also bring decline to species diversity in communities.Controlling the spread of C.caroliniana should be strengthened.