不同生境下的粗梗水蕨所在群落生物多样性的比较

Comparison of Species Diversity of Ceratopteris Pteridoides Community at Different Habitats in China

采用α-多样性指数研究了湖北省4个不同生境(不同湖泊、湿地和水沟)的4个粗梗水蕨群落(梁子湖的湖泊群落LZH1,梁子湖的湿地群落LZH2,赤龙湖的水沟群落CLH1,赤龙湖的湖泊群落CLH2)的基本特征和物种多样性.结果显示:4个粗梗水蕨群落的群落类型、物种组成呈现差异性,LZH1的物种丰富度最高(13种),CLH1的物种丰富度最低(6种).Duncan的多重比较分析表明:CLH2的物种多样性与CLH1和LZH2的物种多样性有显著差异(P<0.05),而与LZH1的物种多样性无差异性.与粗梗水蕨相伴生的入侵植物,在群落CLH1中为喜旱莲子草和水盾草,而在群落LZH2和CLH2中为喜旱莲子草;粗梗水蕨在4个不同生境的群落中的重要值和相对重要值均较低.4个群落之间的物种相似性也呈现差异,最高的是CLH1与CLH2之间(I=53.3),最低的为LZH2与CLH1之间(I=11.8).生境差异和人为干扰影响粗梗水蕨群落植物成分和结构,因此,建立保护点、降低过度养殖和理顺管理体制是保护粗梗水蕨和物种多样性的有效对策.

Species diversity of four Ceratopteris pteridoides communities （LZH1, LZH2, CLH1, CLH2） at four different habitats of Hubei province were analyzed using a-diversity index（Richness index, Shannon-Wiener diversity index, and evenness index）. The results indicated that there was significant differences among four C. pteridoides communities of four different habitats in association type, species composition~ Richness index （R） of LZH1 commu- nity was the highest （13 species）,whereas that of CLH1 community were the lowest （6 species）. Duncan multiple comparison analysis showed that there are significant differences （P^0.05） between CLH2 and CLH1, and between CLH2 and LZH2, but there is no difference between CLH2 and LZH1 in Shannon-Wiener diversity index （H~）. Two kinds of invasive plants Alternanthera philoxeroides and Cabomba caroliniana were associated with C. Dteridoides in communities CLHl,whereas in communities LZH2 and CLH2 only A. philoxeroides. The important value （IV） and the relative important value （Pi） of C. pteridoides at four communities were relatively low. Significant differences were also found among four communities in coefficient of community similarity （I）, I was the highest between CLHland CLH2 （I =53.3）, whereas that was the lowest between LZH2 and CLH1 （I =11.8）. Habitat differentia- tion and disturbance might affect community structure of C. pteridoides. The establishment of protection point, re-ducing the excessive aquaculture and rationalizing the management system is the effective strategies of conservation of the species.