ABSTRACT

Vegetation restoration is a fundamental method of ecological reconstruction in disturbed areas, and revegetation can be achieved by passive (spontaneous succession) and active (human-induced) approaches. Plant community composition, productivity, and diversity were studied in coal mining subsidence areas after 0–15 years of restoration with active (AR) and passive (PR) revegetation approaches in a semiarid region. Moreover, plant community composition, succession, and their relationships with soil variables were analyzed. The results showed that both PR and AR contributed to the recovery of the plant community in terms of plant cover, density, biomass, and diversity, with AR accelerating the recovery of the plant comm unity to a greater extent than PR. Soil moisture and organic matter had close relationships with the plant community variables. The plant communities in PR sites had the same species composition as those in non-subsidence (NS) areas, which led to a more natural plant community in PR than AR sites. Plant community structure in AR sites was altered by the introduced shrubs, with mesophytes developing under the introduced shrubs. These changes produced a different successional trajectory in AR sites from that in NS sites; thus, environmental fluctuations may easily change AR community stability in semiarid environments.

摘要

植被恢复是受干扰地区生态重建的基本方法，植被恢复可以通过被动（自发演替）和主动（人为）两种方式实现。在半干旱地区采用主动 (AR) 和被动 (PR) 重新植被方法恢复 0-15 年后，对采煤沉陷区的植物群落组成、生产力和多样性进行了研究。此外，还分析了植物群落组成、演替及其与土壤变量的关系。结果表明，PR和AR在植物覆盖、密度、生物量和多样性方面都有助于植物群落的恢复，AR比PR在更大程度上加速了植物群落的恢复。土壤水分和有机质与植物群落变量密切相关。PR站点的植物群落与非沉降（NS）区域的植物群落具有相同的物种组成，这导致PR站点比AR站点更自然的植物群落。AR 地点的植物群落结构被引入的灌木改变，中生植物在引入的灌木下发育。这些变化在 AR 站点与 NS 站点产生了不同的演替轨迹；因此，环境波动很容易改变半干旱环境中 AR 群落的稳定性。这些变化在 AR 站点与 NS 站点产生了不同的演替轨迹；因此，环境波动很容易改变半干旱环境中 AR 群落的稳定性。这些变化在 AR 站点与 NS 站点产生了不同的演替轨迹；因此，环境波动很容易改变半干旱环境中 AR 群落的稳定性。