摘要
利用盖度和重要值两个多度指标对北京东灵山地区小龙门林场的５个植物群落进行了研究，以考察样本大小（即样方数量）对多样性测度的影响，并设计了３种方法来确定临界样方数量（即多样性测度趋于稳定时的样方数量）。结果表明，用盖度和重要值作为多度指标进行植物群落多样性的研究是合适的，并且得出的结果也是一致的；当取比例因子ｋ１＝０．２时，计算临界样方数量的第二种方法与直观判断比较吻合；丰富度指数不太稳定，临界样方数量在２０以上（样方面积为５ｍ×５ｍ）；多样性指数Ｄ１最稳定，只需少数几个样方就达到稳定状态，多样性指数ＯＤ最不稳定；均匀度指数Ｊｇｉ也比较稳定，也只需几个样方就达到稳定状态；３个丰富度指数间有确定性关系：Ｒ２＞Ｒ１＞Ｒ３；在各指数达到稳定状态以后，甚至在少数几个样方之后就有ＯＤ＞ＨＰ＞Ｄ＞Ｄ１＞ＤＭ，Ｊｇｉ＞Ｊｓｗ＜＞Ｅａ＞Ｅｓ＞Ｅｈ，其中“＜＞”表示不确定，对乔木层有Ｅａ＞Ｊｓｗ，对草本层有Ｊｓｗ＞Ｅａ，除第３个样地外，对其它４个样地的灌木层也有Ｊｓｗ＞Ｅａ；在大多数情况下，各指数都有或近似地有：草木层＞灌木层＞乔木层。
The number of species in a community,or the species richness,is the oldest and most fundamental concept of diversity.From its estimation we can acquire the information about species extinction rate,and this is important to the diversity conservation.Numerous methods have been proposed for estimating the number of species in a community.Some of them are theoretical sampling based,and others data analytic.The former includes frequentist and Bayesian procedures,and the latter integration of lognormal distribution,resampling methods(jackknife and bootstrap) and extrapolation of species area curves.It has been found that(1)some methods are suitable to animal communities,e.g.most of the theoretical sampling based methods,and some to plant communities,e.g.most of the data analytic methods;(2)they have not yet been compared systematically;(3)there is not as yet a globally preferable method.Therefore,It is suggested that the methods should be assessed systematically through field investigations for various communities and simulations for different conditions.
出处
《生态学报》
CAS
CSCD
北大核心
1997年第6期601-610,共10页
Acta Ecologica Sinica
基金
国家自然科学基金
国家基础重大项目
关键词
生物群落
多样性
测度方法
估计方法
物种数目
community,number of species,species richness,estimation,parametric method,nonparametric method,extrapolation.
