南方稀土矿治理区植物群落特征及其土壤效应

发布时间：2018-05-13 00:14

  本文选题：植物群落 + 土壤效应　； 参考：《福建师范大学》2015年硕士论文

【摘要】：多年来,由于经济的发展,人们对稀土的需求量越来越大,对地表植被产生巨大的破坏作用,随后造成严重的水土流失,进而导致生态系统的退化。生态系统退化严重威胁人类生存与发展,退化生态系统的恢复与重建是当今社会各界关注的焦点问题。因此,如何恢复南方稀土矿区植被,形成自我维持、长效稳定的生态系统,促进矿区生态环境改善和经济协调发展,是该类型矿区生态建设急需解决的问题。本研究以南方典型红壤区长汀县稀土矿治理区为研究对象,选择四个样区(三个稀土矿开采区和—个稀土矿非开采区)进行野外植物样方调查及土壤取样,并对研究区的植物多样性、稀土元素、土壤理化性质、主要水土保持植物根际与非根际土壤氮素含量特征等进行研究,得出以下主要结论：(1)稀土矿区的植物多样性随着治理年限的增加,草本层Patrick丰富度指数、灌木层Alatalo均匀度指数、Shannon-Wiener多样性指数都呈上升的趋势,而草本层Alatalo均匀度指数则反之；四个样区草本层Alatalo均匀度指数都大于灌木层。随着治理年限的增加,芒萁的高度和盖度先缓慢增加后迅速增加,2014年分别达到85cm和90%。(2)四个样区土壤中稀土元素含量大小依次为：下坑(507.37mg/kg)牛屎塘(219.11mg/kg)三洲桐坝(94.91mg/kg)非开采区龙颈(33.07mg/kg),∑L/∑H明显小于1。除非开采区龙颈外,牛屎塘、下坑、三洲桐坝3个稀土矿开采区土壤机械组成总体上是砂粒粉粒粘粒。上层土壤有机质在四个研究区中达到了显著性水平(P0.05),下层土壤全氮、全钾、速效钾在四个研究区之间均不显著。(3)根际比非根际土壤全氮、铵态氮、硝态氮平均分别高出79.7%、34.2%、30.7%,土壤有机碳平均高出164.9%,pH值平均高出0.12个单位。除pH值外,根际土壤与非根际土壤全氮、铵态氮、硝态氮、有机碳之间都差异显著(P0.05)。四种植物根际土壤全氮、硝态氮、铵态氮和有机碳的含量均比非根际土壤含量高。宽叶雀稗、木荷的根际土壤pH值比非根际土壤高,芒萁、枫香则相反。在根际与非根际土壤中,土壤全氮与土壤有机碳之间呈显著正相关,而土壤全氮与土壤铵态氮、土壤全氮与土壤硝态氮之间均无相关性。
[Abstract]:Over the years, due to the economic development, the demand for rare earths is increasing, which has a huge damage to the vegetation, and then causes serious soil erosion, which leads to the degradation of the ecosystem. Ecosystem degradation is a serious threat to human survival and development. The restoration and reconstruction of degraded ecosystem is the focus of attention. Therefore, how to restore the vegetation of the rare earth mining area in the south, form a self-sustaining and stable ecological system, and promote the ecological environment improvement and the coordinated development of the economy in the mining area are the urgent problems to be solved in the ecological construction of this type of mining area. In this study, four sample areas (three rare earth mining areas and one rare earth ore non-mining area) were selected to investigate plant samples and soil samples in Changting County, a typical red soil region in southern China. The plant diversity, rare earth elements, physical and chemical properties of soil, nitrogen content in rhizosphere and non-rhizosphere soil of main soil and water conservation plants were studied. The main conclusions are as follows: (1) the plant diversity in the rare earth mining area increases with the increase of management years, the Patrick richness index of herbaceous layer and the Alatalo evenness index of shrub layer are all increasing, while the Alatalo evenness index of herbaceous layer is vice versa. The Alatalo evenness index of herbaceous layer was higher than shrub layer in four sample areas. As the number of years of governance increases, The height and coverage of Osmunda Osmunda increased slowly at first and then increased rapidly. The REE contents in the soil of the four sampling areas reached 85cm and 90.Y. 2 in 2014, respectively. The order of REE content was: Xiakeng Li 507.37 mg / kg) cattle shitang (219.11 mg / kg); Sanzhou Tongba 94.91 mg / kg); in non-mining area, the content of rare earth elements was 33.07 mg / kg 路kg ~ (-1), 鈭，

本文编号：1880791