十八河铜尾矿库草本植物群落优势种种间关系

Interspecific associations of dominant species in herbaceous plant communities on Shibahe copper mine tailings

为了筛选适宜在铜尾矿库进行植被修复的草本植物种类及其配置模式,笔者采用χ2检验、方差比率法(V R)、联结系数(A C)、Ochiai指数(O I)、M.Gordon稳定性测定、Pearson相关系数、Spearman秩相关系数和生态位等分析方法,对山西中条山矿区十八河铜尾矿库自然定居草本植物群落11个优势种种间关系和生态位进行分析。研究结果表明:1)11个草本植物优势种组成的55个种对中,Pearson相关和Spearman秩相关系数的正负关联比均<1,优势种总体呈不显著负关联;2)11个优势种被划分为3个生态种组,导致其生态种组分化的主导因子是土壤水分条件;3)11个优势种的生态位重叠指数均<0.4,其中芦苇(Phragmites australis)、扁秆荆三棱(Bolboschoenus planiculmis)、垂柳(Salix babylonica)(幼苗)和荆三棱(Scirpus yagara)的生态位宽度较大;扁秆荆三棱、垂柳(幼苗)和荆三棱种对间呈正相关,芦苇与其他优势种多呈负相关。说明十八河铜尾矿库自然定居草本植物群落结构不稳定,处于演替的初期阶段;在未来进行铜尾矿库植被修复时,优势种扁秆荆三棱、垂柳(幼苗)和荆三棱可混合种植,而芦苇宜单种。

[Background]Revegetation is one of the best ways for recovering copper mine tailings and it also shows favorable ecological,social and economic benefits.Screening the best pioneer herbaceous plant species and their combinations are the prerequisite for revegetation on copper mine tailings.[Methods]Based on the field investigation in naturally-colonized plant communities on Shibahe copper mine tailings of Zhongtiaoshan mining area of Shanxi,we analyzed the interspecific associations and indexes of niche of 11 dominant herbaceous species.We used variance ratio method(V R),M.Godron method,niche breadth,niche overlap and interspecific association methods,includingχ2-test,association coefficient(A C),Ochiai index(O I),Pearson correlation coefficients and Spearman rank correlation coefficients.[Results]1)The positive and negative ratios associations of Pearson correlation coefficient and Spearman rank correlation coefficient of 55 species-pairs among 11 dominant herbaceous species in naturally colonized herbaceous plant communities were<1 and most species-pairs had no significant interspecific correlation.The overall association of 11 dominant species had also no significantly negative correlation,which was consistent with the results of variance ratio(V R),A C and O I.2)The 11 dominant herbaceous species were classified into 3 ecological species groups by clustering analysis based on the Spearman rank correlation coefficients and most species-pairs belonging to the same ecological species group with positive correlation.Soil moisture was the key factor caused the differentiation of 3 ecological species group.3)The niche overlap index of 11 dominant herbaceous species was<0.4 and its results were consistent with the interspecific associations.Among them,the dominant species Phragmites australis,Bolboschoenus planiculmis,seedling of Salix babylonica and Scirpus yagara with great niche breadth had strong ecological adaptability to tolerate the poor soil of copper mine tailings,and thus was recommended as the best pioneer species for future revegetation on copper mine tailings.The dominant species-pairs B.planiculmis-seedling of S.babylonica,B.planiculmis-S.yagara,and S.yagara-seedling of S.babylonica showed significantly positive associations,while the P.australis showed significantly negative associations with other 10 dominant species.[Conclusions]The community structure of the naturally colonized herbaceous plants on Shibahe copper mine tailings of Zhongtiaoshan mining area was unstable,and they were still in the early stage of succession.The interspecific associations were loose and no obvious competitive relationship between dominant herbaceous species.The dominant species B.planiculmis,seedling of S.babylonica and S.yagara could be mixed planting in future revegetation on local copper mine tailings,while P.australis couldn’t be mixed planting with other 10 dominant species.