煤矿复垦地不同恢复阶段植物群落功能群结构与生物多样性变化

选取黄土高原区黑岱沟露天煤矿不同复垦阶段(1995～2010年)样地4块,以原地貌样地为对照,以时空替代的方法,对煤矿复垦地的植物群落的功能群结构及生物多样性进行研究.结果表明:(1)随着复垦时间的延长,植物群落功能群组成以多年生禾草和多年生杂类草为主,其累积优势度均呈现增加的趋势,而一、二年生草本的累积优势度减小;复垦初期,群落功能群单一、组成种类贫乏,多为一、二年生植物;复垦后期,羊草及冰草逐步出现,复垦地最终形成以克氏针茅、本氏针茅、赖草及糙隐子草为主的植物群落.(2)复垦过程中,中生植物及中旱生植物所占比例逐步增加,而旱生植物比例逐步减少;多年生禾草及多年生杂类草生物量随着复垦时间的增加而递增,而一、二年生草本植物生物量递减;群落总生物量呈先急剧增加、又急剧减少、后缓慢增加的规律.(3)群落的Shan-non-Wiener多样性指数(H)、Patrick丰富度指数(Pa)及Pielou均匀度指数(JP)随着复垦时间延长而增加.

Structure and Biodiversity of Functional Group in Different Restoration Stages in Coal Mine Reclamation Land

A spatial series representing the temporal sequence of vegetation restoration on opencast coal mine was used to investigate structure and biodiversity of functional group of reclamation land in Loess Plateau.Five plots,which were basically the same habitats,were selected in Heidaigou opencast coal mine,including of one original landscape plot (control) and four reclamation plots in different reclamation stages (from 1995 to 2010).The results showed that:With the increase in reclaiming time,the composition of perennial grass and perennial forb dominated,and their cumulative dominances showed an increasing trend,but the cumulative dominance of annual or biennial herb reduced.In initial stage of reclamation,the functional groups were simple,poor composition of species,mostly annual or biennial herb.Later stage,Leymus chinensis and Agropyron cristatum appeared.Final,reclamation land engendered a natural community consisted of Stipa krylovii,Stipa bungeana,Leymus secalinus and Cleistogenes squarrosa,etc.In the course of the reclamation,the percentage of mesophyte and mesoxerophytes increased gradually.On the contrary,the percentage of xerophytes reduced.Along with the increase of reclamation time,the biomass of perennial grass and perennial forb increased,while the biomass of annual or biennial herb plant decreased.The total biomass showed the trend of first increased sharply then dropped sharply,and followed by a gradual increase.With the increase of reclamation time,the Shannon-Wiener diversity index (H),Patrick richness index (Pa) and Pielou evenness index (JP) increased.