内蒙古高寒露天煤矿排土场植被恢复研究

探究不同恢复年限对于露天煤矿植被群落变化和植物个体生长的影响,进一步加强生态环境保护与生态修复治理措施。以内蒙古高寒露天煤矿排土场恢复4年(2018-2021年)的植物群落为研究对象,采用样方调查方法,对样地内植物群落进行调查,设置草本样方(1 m×1 m)和灌木样方(5 m×5 m),记录植物物种组成、高度及盖度等指标,计算Shannon-Wiener多样性指数、Simpon指数、Pielou均匀度指数和物种重要值。探讨不同的恢复年限植物群落变化特征和优势植物的养分吸收,为矿区人工植被恢复提供科学依据。结果表明:(1)矿区排土场植物群落物种数、生物量和群落多样性均随着恢复年限的增加而显著增加。总物种数从恢复第1年的16种增加到恢复第4年的31种,主要是由于非人工种植植物从6种增加到19种导致,特别是在恢复第2年增加显著,然后趋于平稳,这说明恢复第2年是物种增加关键的时期;(2)随着恢复年限的增加,生物量和多样性指数显著增加;矿区植被优势物种多以禾本科披碱草(Elymus dahuricus)、无芒雀麦(Bromus inermis);豆科植物苜蓿(Medicago sativa)、草木樨(Melilotus officinalis)、沙打旺(Astragalus adsurgens)、锦鸡儿(Caragana sinica);菊科植物大籽蒿(Artemisia sieversiana);十字花科油菜(Brassica napus)和胡颓子科沙棘(Hippophae rhamnoides)为主。(3)比较不同优势植物叶片、茎和根的氮(N)、磷(P)和钾(K)含量发现,草本优势种中菊科和豆科植物显著高于禾本科植物。灌木优势种中沙棘茎的N含量和P含量显著高于锦鸡儿。研究认为,在排土场植被恢复初期(4年)的物种选择上,豆科植物和菊科植物是草本植物首选的先锋物种,另外,沙棘是灌木首选的物种。

Study on Plant Rehabilitation at Dump Sites of Open-pit Mine in Inner Mongolia

To explore the effects of different restoration years on vegetation community changes and individual plant growth in open-pit coal mines, and further strengthen ecological environmental protection and ecological restoration measures. Taking the plant community of Inner Mongolia alpine open-pit coal mine during the four years of restoration (2018-2021) as the research object, we adopted the quadrat survey method to investigate the plant community in the sample site. The herb quadrat (1 m×1 m) and shrub quadrat (5 m×5 m) were set to record the plant species composition, height and coverage. Shannon-Wiener diversity index, Simpon index, Pielou evenness index and species importance were calculated. The change characteristics of plant community and nutrient uptake of dominant plants in different restoration years were discussed to provide scientific basis for artificial vegetation restoration in mining areas. The results showed that: (1) With the increase of restoration years, the total species number, biomass and diversity index increased significantly. Total species number was increased from 16 to 31 which from the first year to the fourth year after rehabilitation. This due to the non-planted species increased from 6 to 19. Especially the species number was significantly increased on the second year, then steady on third and fourth year. It demonstrated that second year was key year for plant rehabilitation. (2) The dominant species were Gramineae plants Elymus dahuricus, Bromus inermis; Leguminosae plants Medicago sativa, Melilotus officinalis, Astragalus adsurgens, Caragana sinica; Artemisia sieversiana (Compositae); Brassica napus (Brassicaceae) and Hippophae rhamnoides (Elaeagnaceae) in study sites. (3) Compared the nutrient (N, P and K) uptake among dominated species, there were higher nutrient contents of Legumes and compositae than Gramineae plants in herbaceous plants. The N content and P contents in the stem of H. rhamnoides were significantly higher than that of Caragana sinica in shrub dominant species. According to the study, in the initial stage of vegetation restoration (4 years), legumes and compositae were the preferred pioneer species of herbaceous plants, while H. rhamnoides is the preferred species of shrubs.