Altitudinal Pattern Of Plants Species Richness In Meili Snow Mountain And A Test Of Rapoport’s Rule

Species richness is an important index to measure the degree of regional species diversity, studying the distribution pattern and influencing factors of plant species richness has important significance to the protection of biological diversity. Especially, the spatial distribution pattern and the formation mechanism of species richness has always been one of hot issues in the field of ecology.Rapoport’rule is a guide rule on the phenomenon that latitude distribution width of animal and plant species tapers off from high latitudes to low latitudes.In the macroscopic ecology theory system, Rapoport’rule is regarded as an important hypothesis. Verification and research of the Rapoport’rule has always been one of the very concerned problems for ecologists.In this paper, species richness of plants distributing along altitudinal gradient in meili snow mountain was analyzed; meanwhile whether Rapoport’rule exists or not in altitudinal gradient of this region was tested by methods including Stevens law, Rohde’s mid-point method, Pagel upper law, Letcher and Harvey’s cross—specie rule, and grouping test designed for cutting down the mid-domain effects. Here are the main conclusions:(1)In general, Meili snow mountain plant species richness rised with elevation increased; after the rising, it decreased so that it’s a typical unimodal pattern (R2=0.9501, P<0.001). Species number reached the highest value at an altitude of about3500m. In all elevations, wide-distributing plant species accounted for a larger proportion of the elevation of all species, all plant species in this region were largely effected by the mid-domain effects.(2) Whether Rapoport’rule exists or not was tested by Stevens method, Pagel method, Rohde’s mid-point method, Letcher and Harvey’s cross—species method. Due to the differences between various method, the results were different from each other, however, all results could not support the exist of Rapoport rule in general; after the test by sectioning method, all results consistently showed that there was no Rapoport effect in this area.(3) In Rapoport’rule validation, the mid-domain effects should be eliminated. With the traditional test method, the mid-domain effects had caused a difference between the results; but with sectioning test method, which could cut off the mid-domain effects, a consistent result was concluded. Therefore, sectioning test method could well cut off the mid-domain effects on the test reaults of Rapoport rule.(4) This study found that:the universality of Rapoport’rule may not exist, as far as the current research, Rapoport’ rule might just meet specific conditions to form some regional effect, but due to the current insufficient of research level and depth, qualitative conclusions on Rapoport rule could not be concluded. More in-depth, detailed and comprehensive study should be done.