采煤塌陷对地表植物群落特征的影响

为了研究采煤塌陷对地表植被组成及其多样性的影响,对陕西省神府-东胜补连塔煤矿采煤塌陷区不同塌陷年限(2、7、12、17 a)区域和未塌陷区域(对照)植被进行抽样调查与分析. 结果表明:该区域共有14科39属46种植物,主要为草本植物；采煤塌陷对植被种类组成、物种分布有很大影响,导致植物种类显著减少31.03%~44.83%. 塌陷区优势种较对照区有较大变化,优势种由多年生草本植物演变为一二年生草本植物；但是不同塌陷年限区域植物优势种基本稳定,主要为看麦娘(Alopecurus aequalis)、烛台虫实(Corispermum candelabrum)、刺叶藜(Chenopodium aristatum)等. 采煤塌陷导致植株密度显著下降58.62%~68.00%、物种丰富度显著下降17.43%~27.00%、Margalef丰富度指数显著降低4.07%~22.76%,但植被盖度差异不显著. 采煤塌陷显著影响植物群落多样性,其中,塌陷12和17 a样地植被Margalef丰富度指数和Shannon-Wiener多样性指数较塌陷2 a样地显著提高. 群落排序结果表明,物种分布与塌陷有明显相关性. 塌陷区植株密度及其植被组成中多年生草本种数很难恢复到对照区水平,植被恢复进程十分缓慢. 

Effects of Land Subsidence by Mining on the Plant Community

Abstract: Species composition and distribution can be greatly affected by land subsidence due to mining. Species richness and plant density, as well as plant coverage, can be significantly reduced. The influence of mining subsidence on vegetation was evaluated by comparing areas with various periods since subsidence (2,7, 12 and 17 a) with areas having no subsidence (control) in the Shenfu-Dongsheng coal mining region. Among these areas, a total of 46 species belonging to 39 genera and 14 families were identified. The species richness decreased by 31.03%-44.83% in the subsidence groups compared to the control. The dominant species in the subsidence areas shifted from perennial herbs to biennial herbs, but there was no significant change in areas without subsidence. The dominant species in the subsided areas were Alopecurus aequalis, Corispermum candelabrum and Chenopodium aristatum. Furthermore, the plant density in the subsided areas significantly decreased by 58.62%-68.00% compared to the control; plant coverage was reduced by 17.43%-27.00%; and the Margalef diversity index declined by 4.07%-22.76%. Although the Margalef diversity index decreased in all subsidence groups, the Margalef and Shannon-Wiener diversity indices in the 12 and 17 a subsidence groups were much higher than those for the 2 a group. Lastly, ordination results for the plant communities showed that the distribution of species was correlated with the period of subsidence. The results demonstrate that the recovery of the density of vegetation and perennial herbaceous species in subsided areas is difficult and very slow.