本文選題：植物群落 + 土壤效應(yīng)��； 參考：《福建師范大學(xué)》2015年碩士論文

【摘要】：多年來,由于經(jīng)濟的發(fā)展,人們對稀土的需求量越來越大,對地表植被產(chǎn)生巨大的破壞作用,隨后造成嚴(yán)重的水土流失,進而導(dǎo)致生態(tài)系統(tǒng)的退化。生態(tài)系統(tǒng)退化嚴(yán)重威脅人類生存與發(fā)展,退化生態(tài)系統(tǒng)的恢復(fù)與重建是當(dāng)今社會各界關(guān)注的焦點問題。因此,如何恢復(fù)南方稀土礦區(qū)植被,形成自我維持、長效穩(wěn)定的生態(tài)系統(tǒng),促進礦區(qū)生態(tài)環(huán)境改善和經(jīng)濟協(xié)調(diào)發(fā)展,是該類型礦區(qū)生態(tài)建設(shè)急需解決的問題。本研究以南方典型紅壤區(qū)長汀縣稀土礦治理區(qū)為研究對象,選擇四個樣區(qū)(三個稀土礦開采區(qū)和—個稀土礦非開采區(qū))進行野外植物樣方調(diào)查及土壤取樣,并對研究區(qū)的植物多樣性、稀土元素、土壤理化性質(zhì)、主要水土保持植物根際與非根際土壤氮素含量特征等進行研究,得出以下主要結(jié)論：(1)稀土礦區(qū)的植物多樣性隨著治理年限的增加,草本層Patrick豐富度指數(shù)、灌木層Alatalo均勻度指數(shù)、Shannon-Wiener多樣性指數(shù)都呈上升的趨勢,而草本層Alatalo均勻度指數(shù)則反之；四個樣區(qū)草本層Alatalo均勻度指數(shù)都大于灌木層。隨著治理年限的增加,芒萁的高度和蓋度先緩慢增加后迅速增加,2014年分別達到85cm和90%。(2)四個樣區(qū)土壤中稀土元素含量大小依次為：下坑(507.37mg/kg)牛屎塘(219.11mg/kg)三洲桐壩(94.91mg/kg)非開采區(qū)龍頸(33.07mg/kg),∑L/∑H明顯小于1。除非開采區(qū)龍頸外,牛屎塘、下坑、三洲桐壩3個稀土礦開采區(qū)土壤機械組成總體上是砂粒粉粒粘粒。上層土壤有機質(zhì)在四個研究區(qū)中達到了顯著性水平(P0.05),下層土壤全氮、全鉀、速效鉀在四個研究區(qū)之間均不顯著。(3)根際比非根際土壤全氮、銨態(tài)氮、硝態(tài)氮平均分別高出79.7%、34.2%、30.7%,土壤有機碳平均高出164.9%,pH值平均高出0.12個單位。除pH值外,根際土壤與非根際土壤全氮、銨態(tài)氮、硝態(tài)氮、有機碳之間都差異顯著(P0.05)。四種植物根際土壤全氮、硝態(tài)氮、銨態(tài)氮和有機碳的含量均比非根際土壤含量高。寬葉雀稗、木荷的根際土壤pH值比非根際土壤高,芒萁、楓香則相反。在根際與非根際土壤中,土壤全氮與土壤有機碳之間呈顯著正相關(guān),而土壤全氮與土壤銨態(tài)氮、土壤全氮與土壤硝態(tài)氮之間均無相關(guān)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，

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