关于种域的Rapoport法则检验、算法比较及中域效应消减--以云南无量山种子植物为例

On the Test of the Rapoport's Rule,Algorithm Comparison,and Weakenning of Mid-Domain Effec——With a Case Study on the Seed Plants in Mt. Wuliang,Yunnan Province

Rapoport法则是物种分布幅度在环境梯度上的统计分布特征,与物种丰富度的梯度格局密切相关。关于Rapoport法则普适性检验的争论被认为与数据统计方法有关,但对这些算法有效性的评价还很少见。以云南无量山种子植物在海拔梯度上的分布数据为例,比较4种常用的Rapoport法则检验算法,并按照海拔分布幅度等级将全部物种分成4组后,再比较不同算法的结果。分析表明,中点法和上限法的检验结果受中域效应的显著影响,Steven方法受影响较小,而逐种法可以回避MDE影响。按海拔幅度分组统计,可以显著削弱MDE的影响,但是数据本身误差的效应有所放大。综合所采用的分析方法,无量山种子植物海拔分布整体格局中存在Rapoport法则;而山顶附近存在局部的反Rapoport法则现象,与植物群落类型的更替对应,可能与山顶气候效应有关。

The Rapoport＇s rule concerns the statistic distribution characteristic of species range along a specific environmental gradient,which is closely related with the pattern of species richness along the same gradient.The long standing controversy on the general validity of Rapoport＇s rule has been found to partially be caused by the algorithms applied.However,the assessments and comparisons are still rare concerning the validity of the algorithms.In this paper,the data of altitudinal distribution of the seed plants in Mt.Wuliang at south Yunnan Province is used,to compare the 4 commonly applied testing algorithms for the validity of the Rapoport＇s rule.We then break the species into four categorys according to the altitudinal range size（etc.200 m,201~500 m,501~1 000 m,and 1 000 m）,and compare the results of testing with 4 methods on the same set of data.Both the results of midpoint method and Pagel＇s upper limit method are strongly suffered from the impact of MDE,while the bias on Steven＇s method is much weaker.In contras,the cross-species algorithm is free of MDE.Our categorizing strategy obviously weakened the MDE on the patterns got through first three methods,but released the impact from stochastic error in the data per se.In a summary,we got consistent results in support of the Rapoport＇s rule in the altitudinal pattern of species range of seed plants in Mt.Wuliang.A local pattern inverse to the Rapoport＇s rule near the mountain top corresponds to the exchange of vegetation types,might due to the local climate effect on species distribution.