桂林岩溶石山密花树群落主要物种的种间关联及群落稳定性

Interspecific associations of main species and community stability of Myrsine seguinii community in Karst hills of Guilin,southwestern China

研究群落内主要物种的种间关联及群落稳定性,有助于正确地认识种间关系和物种共存机制,进而能为植被的恢复与重建以及生物多样性保护等提供理论依据。然而桂林岩溶石山密花树群落主要物种的种间关联及群落稳定性仍不明确。基于群落调查数据,采用方差比率法(VR)、χ^(2)检验、Pearson相关检验、Spearman秩相关检验和M.Godron稳定性等方法,对该群落主要物种的种间关联及群落稳定性进行研究。结果表明:(1)该群落乔木层、灌木层和草本层主要物种间的总体关联性均呈显著负关联;(2)χ^(2)检验结果显示,各层次绝大部分种对均无显著关联,种间关联较松散,各物种间呈独立分布格局;(3)Pearson相关检验和Spearman秩相关检验发现,各层次绝大部分种对均呈不显著相关,种间相关性较弱;(4)M.Godron稳定性结果表明,整个群落及其各垂直层次的稳定性测定结果均远离20/80,皆处于不稳定状态。研究显示桂林岩溶石山密花树群落种间关联较松散,各物种呈相对独立分布格局,群落处于不稳定的演替早期阶段。因此,在岩溶地区植被恢复与重建过程中,应将资源利用方式、生物学特征和生态学习性相近,对生境要求相似的优势乡土物种搭配在一起。此外,可采取适当的抚育措施,调节种间关系,提高群落稳定性。

Exploring the interspecific associations of main species and community stability of plant community will help to better understand the interspecific relationship and the mechanism of species coexistence,and thereby provide theoretical basis for the restoration and reconstruction of vegetation,biodiversity protection,and sustainable utilization of the plant community.However,little is known about the interspecific associations of main species and community stability of Myrsine seguinii community in Karst hills of Guilin,southwestern China.To investigate the interspecific associations of main species and community stability of M.seguinii community,a total of 30 plots were set up and studied by using a series of quantitative analysis methods including the variance ratio(VR),Chi-square test(χ^(2) test),Pearson′s correlation coefficient test,Spearman′s rank correlation coefficient test,and M.Godron stability analysis.The results showed that:(1)the overall interspecific associations among the main species in the tree layer,shrub layer and herb layer of the community showed significantly negative associations.(2)The results of the Chi-square test indicated that there was no significant association among most species pairs in each vertical layer,reflecting a weak association among the various species pairs,and most of the species showed an independent distribution pattern.(3)Pearson′s correlation coefficient and Spearman′s rank correlation tests showed that most species pairs in each vertical level were not significantly correlated,and the correlation among species was weak.(4)M.Godron stability analysis indicated that the ratios of cumulative inverse of species number to the cumulated relative frequency ratios of species in tree layer,shrub layer,herb layer and the whole community were 27.93/72.07,30.40/69.60,29.05/70.95 and 27.52/72.48,respectively,distinctly different from the stability point(20/80),indicating that the whole community and each vertical layer of the community were in an unstable state.These findings showed that the community was at the early stage of succession,with loose interspecific association and independent species distribution pattern.Therefore,the dominantly native species with similar resource utilization patterns,similar biological and ecological characteristics and similar habitat requirements should be planted together in the process of vegetation restoration and reconstruction in Karst areas.In addition,appropriate human management measures could be adopted to optimize interspecific relationships to improve community stability.