南京外秦淮河优势草本植物生态位和种间联结性研究

Niche and interspecific association of dominant herbaceous plants in the outer Qinhuai River,Nanjing City

【目的】探究南京外秦淮河优势草本植物的生境适应性、种间联结性及群落的发展状态,为秦淮河区域的植被生态恢复及河流生态廊道构建提供参考。【方法】基于群落调查数据,采用生态位宽度、生态位重叠值、生态位相似性分析南京外秦淮河优势草本植物生态位特征;采用总体关联性分析、χ^(2)检验、种间联结系数(AC)、共同出现百分率(PC)、Pearson相关检验和Spearman秩相关检验分析种间联结性特征;采用M.Godron群落稳定性分析群落稳定性特征。【结果】(1)本次调查共记录124种草本植物,其中酸模生态位宽度值最大。(2)外秦淮河优势草本植物种间总体关联性呈不显著正联结。(3)χ^(2)检验、Pearson相关检验和Spearman秩相关检验发现,优势物种种间联结性较弱,物种独立性较强。(4)AC值≥0.6的种对有18对,PC值≥0.7的种对数有5对,优势植物种间联结性较弱。(5)M.Gordon分析结果表明,交点与稳定点坐标偏离较远,群落目前处于不稳定状态。【结论】南京市外秦淮河草本植物群落优势物种间生态位差异较大,总体关联性呈不显著负联结,χ^(2)检验、AC值、PC值、Pearson相关检验和Spearman秩相关检验结果均表明群落内种间联结性较低,种间结构较为松散,物种独立性较强,群落处于不稳定的演替阶段。因此,亟须加强秦淮河流域的生态修复工作,增强群落稳定性。

【Objective】Exploring the ecological niche,interspecific association and community stability of dominant herbaceous plants in the Outer Qinhuai River will provide a theoretical basis and practical reference for the ecological restoration of vegetation and the construction of a river ecological corridor.【Method】Based on community survey data,niche width,niche overlap,and niche similarity were used to analyze niche characteristics,total association analysis,χ^(2)test,interspecific association coefficient(AC)value,common occurrence percentage(PC)value,Pearson’s correlation coefficient test,Spearman’s rank correlation coefficient test were used to analyze the characteristics of interspecific.【Result】(1)A total of 124 species of herbaceous plants were identified in this survey.The niche width of Rumex acetosa was the largest.(2)The overall correlation among the dominant herbaceous species in the Outer Qinhuai River showed no significant positive association.(3)Theχ^(2)test,Pearson’s correlation coefficient test,and Spearman’s rank correlation coefficient test showed that most species pairs were not significantly correlated and the correlation among species was weak.(4)The 18 pairs showed AC value≥0.6 and five pairs showed PC value≥0.7,indicating that the association between dominant species was weak.(5)M.Gordon’s stability analysis indicated that the coordinates of the intersection point and stable point deviated significantly,and the community was in an unstable state.【Conclusion】Dominant species of herbaceous plant communities in the outer Qinhuai River,Nanjing City show a wide difference in niche.The overall correlation among the dominant herbaceous species did not show a significant positive association.The interspecific structure was loose,species independence was strong,and the community was in an unstable succession stage.To improve community stability,it is necessary to strengthen the ecological restoration of the Qinhuai River basin.