草原矿区排土场不同植被配置类型生态恢复

Ecological restoration of different vegetation collocations of coal mine dump in typical steppe

以典型草原大型露天煤矿排土场为对象,研究不同植被配置类型人工、半人工植物群落的植物组成、群落结构、物种多样性及土壤主要养分变化。结果表明,自然恢复的排土场边坡主要以一、二年生植物为主,种类单一,草本层低矮,采取人工植被恢复措施的试验区植物种类明显增加,4种不同植被配置类型试验样地内共出现34种植物,分属13科33属。排土场边坡人工植被恢复一段时期后(4～5 a),植物群落优势种主要以人工种植的植物为主,主要伴生种为多年生杂类草草木樨状黄芪(Astragalus melilotoides)、蒙古虫实(Corispermum mongolicum),禾本科植物克氏针茅(Stipa krylovii)、狼尾草(Pennisetum alopecuroides),以及一、二年生植物刺藜(Chenopodium aristatum)、猪毛菜(Salsola collina)等。4种不同植被配置类型中,灌草群落(Ⅱ) Shannon多样性指数、Pielou均匀度指数数值均最大,土壤全氮、有机质含量也较高,说明排土场采取柠条+紫花苜蓿的灌草植被配置模式生态恢复效果较好,研究结果可为草原矿区植被恢复提供参考依据。

The botanical composition,community structure,species diversity and soil nutrients of artificial and semi-artificial plant community were investigated under different vegetation collocation conditions in coal mine dumps of a typical steppe. The results showed that annuals and biennials dominated in exposed slopes under natural restoration,with simple species composition and low height of community. Plant species richness significantly increased in the artificial vegetation recovery area. There were 34 species belonging to 13 genera and 33 families observed in the four experimental sites of different vegetation collocations. The plant community was dominated by planted species,accompanied with Astragalus melilotoides,Corispermum mongolicum,Stipa krylovii,Pennisetum alopecuroide,Chenopodium aristatum,and Salsola collina after restoration on coal mine dump slope( 4-5 a). Among the four different vegetation collocations,the community collocation of shrubs and herbs( Ⅱ) had the highest Shannon diversity index and Margalef richness index,and soil total nitrogen and organic matter contents. Our results indicated that artificial collocation of shrubs and herbs of Medicago sativa + Caragana korshinskii had better performance in ecological restoration of coal mine dump in typical steppe,which provided reference for the vegetation restoration of coal mining area in the steppe.