受损矿区草原群落物种多样性和地上生物量对覆土厚度的响应

为修复库尔木图矿区受损草原植被群落,对矿区受损草原实施覆土0,10,14和18 cm恢复措施,实地调查分析群落盖度、高度、地上生物量和物种多样性,以研究不同覆土厚度对矿区受损草原群落物种多样性和生物量的影响。结果表明,1)覆土厚度在14和18 cm时,矿区草地植物种类和数量频度最多,物种组成最为丰富,且随着覆土厚度的增加,草地植物群落的盖度、高度和地上生物量呈逐渐增加趋势,但覆土14和18 cm草地的植物高度、盖度和地上生物量差异不显著。2)在4种覆土厚度样地中,覆土14 cm草地的物种丰富度指数和多样性指数均最高,均匀度指数最低,具体表现为:群落均匀度指数(J_sw和Ea)排列顺序为覆土0 cm>覆土18 cm>覆土10 cm>覆土14 cm,群落丰富度指数(R和Ma) 为覆土14 cm>覆土10 cm>覆土18 cm>覆土0 cm,群落多样性指数(D和H')为覆土14 cm>覆土18 cm>覆土10 cm>覆土0 cm。3)不同覆土厚度样地群落生产力与Shannon-Wiener和Simpson多样性指数之间呈弱正相关关系。因此,综合考虑该地区恢复受损草原的经济投入和所产生的生态效益,进行草原植被生态恢复的适宜覆土厚度为14 cm。

Grassland community species diversity and aboveground biomass responses to difference in cover soil thickness in restoration after mining damage

This experiment examined different options for restoration of damaged steppe vegetation in the Kurt Kizu mining area,Xinjiang province,China.Different depths of cover soil (0,10,14,and 18 cm)were applied to mine-damaged steppe,and ground cover,height,aboveground biomass and species richness,diversity and evenness of the vegetation were measured.Key results were:1)The number of species present and the diversi-ty were highest when cover soil was applied at a thickness of 14 or 18 cm.The cover,height,and aboveground biomass of the vegetation generally increased with the thickness of cover soil,but the differences between 14 and 18 cm cover soil thickness were not statistically significant.2)Species richness indices (R and Ma)ranked:14 cm cover soil thickness>10 cm cover soil thickness>18 cm cover soil thickness>0 cm cover soil thickness,while diversity indices (D and H′)ranked:14 cm cover soil thickness>18 cm cover soil thickness>10 cm cov-er soil thickness>0 cm cover soil thickness.The community evenness indices (J sw and Ea)showed an inverse ranking to richness and diversity with 0 cm cover soil thickness>18 cm cover soil thickness>10 cm cover soil thickness>14 cm cover soil thickness.3)There was a low positive correlation between community productivity and Shannon-Wiener and Simpson indices.Therefore,for the Kurt Kizu mining area,considering economic cost against ecological benefits when restoring damaged steppe,the appropriate cover soil thickness for ecologi-cal restoration of grassland vegetation is 14 cm.