南亚热带常绿阔叶林群落及其卫星样地物种多样性特征

Species diversity characteristics of lower subtropical evergreen broad⁃leaved forest community and its satellite plots

群落生物多样性的研究一直备受关注。鼎湖山植被资源丰富,对其典型植物群落及其卫星样地物种多样性状况进行探索是一项非常有意义的研究工作。以鼎湖山20 hm^(2)样地及其周边5个1 hm^(2)卫星样地为研究对象,分别从种面积关系、α多样性和β多样性几个角度进行分析,研究发现:(1)20 hm^(2)南亚热带常绿阔叶林鼎湖山(DHS)大型固定样地经过10年的更新演替,总个体数出现了爆发式增长。DHS样地周边5个卫星样地之间总个体数差异较大,按个体数进行排序:1号(南亚热带山地常绿阔叶林)>3号(南亚热带常绿阔叶林)>5号(南亚热带针阔混交林)>4号(南亚热带常绿针叶林)>2号(南亚热带沟谷雨林)卫星样地。(2)DHS大样地的物种并未达到饱和,卫星样地群落可以有效补充该区域的物种。(3)DHS大样地的α多样性较高;卫星样地之中,2号样地的物种多样性最高,其次是3号样地,继而是1号和4号样地,最后是5号样地。除了2号样地由于大量大树和巨树的存在使得物种均匀度提升,从而导致多样性指数值偏大以外,其它样地的结果呈现出海拔高度与多样性正相关。(4)DHS大样地与其3号卫星样地处于相近演替阶段,因此物种相似度最高。DHS样地与其4号卫星样地(马尾松林)演替阶段相差最远,物种差异性也最大,Bray⁃Curtis指数检测出仅有5%的物种相同。卫星样地之间的β多样性检验显示:南亚热带常绿针叶林(马尾松林)与南亚热带针阔混交林的演替阶段相近,物种相似度最高,Bray⁃Curtis指数表明84%的物种相同;其他卫星样地群落间物种差异较大。故对于鼎湖山南亚热带常绿阔叶林群落的多样性研究,在考虑典型大样地群落的基础上,仍需要统筹考虑卫星样地,方可更完整地获取该区域植被群落的多样性特征。

Community biodiversity research has been attracting much attention.Dinghu Mountain is rich in vegetation resources.It is very meaningful to compare and explore the species diversity of its typical plant communities and satellite plots.In this study,20 hm^(2) plot and five 1 hm^(2) satellite plots in Dinghu Mountain were both used as research objects for the first time,analyzed and compared from the aspects of species area relationship,alpha diversity and beta diversity.Research findings are as follows.(1)After 10 years of renewal succession,abundance of 20 hm2 south subtropical evergreen broad⁃leaved forest(DingHu Shan large⁃scale plot)showed an explosive growth in 2015.The total number of individuals among five 1 hm^(2) satellite plots varied greatly.Sort by number of individuals:plot 1>plot 3>plot 5>plot 4>plot 2.(2)20 hm^(2) plot was not saturated with species,and the surrounding satellite plots can effectively complement and represent species in the region.(3)The DHS large⁃scale plot has a higher alpha diversity.Among satellite plots,plot 2 had the highest species diversity,followed by plot 3,plot 1 and 4,and finally plot 5.The diversity index of plot 2 was relatively large,due to there were large number of large trees and giant trees in plot 2.The results of other plots showed a positive correlation between altitude and diversity,except plot 2.(4)The DHS large⁃scale plot and its satellite plots were in the similar succession stage,so the species similarity was the highest.The difference between DHS plot and its satellite plot 4(Pinus massoniana forest)in succession stage was the farthest,so the species difference was also the largest,bray⁃curtis index detected only 5%of the species were same.Theβdiversity test between satellite sites shows that:the succession stages of south subtropical evergreen coniferous forest(Pinus massoniana forest)and south subtropical coniferous broadleaf mixed forest were similar,with the highest species similarity,and the bray⁃curtis index showed 84%of the species were same.Therefore,it is not only necessary to calculate the DHS plot,but also to consider the surrounding satellite plot as a whole,so as to obtain the diversity characteristics of the whole community in Dinghushan National Nature Reserve more completely.