本文選題：荒漠草原 + 圍封年限　； 參考：《寧夏大學(xué)》2016年碩士論文

【摘要】：封育禁牧作為重要的生態(tài)恢復(fù)措施,所帶來的生態(tài)效應(yīng)已逐漸成為恢復(fù)生態(tài)學(xué)研究的焦點(diǎn)。由于植被-土壤-微生物系統(tǒng)C、N、P循環(huán)是在生態(tài)系統(tǒng)內(nèi)部之間相互轉(zhuǎn)換的,系統(tǒng)研究植物-土壤C、N、P在植物與土壤中的交換過程與格局,深入理解封育禁牧生態(tài)恢復(fù)過程中系統(tǒng)各組分之間的化學(xué)計(jì)量學(xué)協(xié)變關(guān)系,對(duì)揭示荒漠草原生態(tài)系統(tǒng)穩(wěn)定性維持機(jī)理具有重要意義。本研究以寧夏境內(nèi)荒漠草原為研究對(duì)象,通過對(duì)比分析未圍封、圍封5、8、12、15年樣地植物、土壤碳、氮、磷以及土壤微生物量碳、氮與土壤酶活性的變化過程與規(guī)律,分析荒漠草原不同圍封年限對(duì)植物、土壤與土壤微生物的影響。得到如下研究結(jié)論：1.圍欄后,荒漠草原在消除放牧干擾的情況下,植物的生長(zhǎng)得到一定的恢復(fù),主要表現(xiàn)為植物地上部分的生物量與放牧樣地的植物地上生物量相比,圍封5、8、12和15年樣地的植物地上生物量均呈增加的變化趨勢(shì)。植物的高度和蓋度等植被特征也表現(xiàn)出相似的變化規(guī)律,高度、蓋度、地上生物量均隨著圍封年限的延長(zhǎng)表現(xiàn)出先增加后減少的變化趨勢(shì)。圍封樣地的優(yōu)勢(shì)種植物地上部分碳、氮含量均高于未圍封樣地,且圍封樣地的優(yōu)勢(shì)種植物地上部分C：P比值與N：P比值均高于未圍封樣地。2.隨著圍封時(shí)間的延長(zhǎng),土壤容重先減小后增大；土壤含水量則表現(xiàn)出相反的變化規(guī)律,即先升高后降低；同時(shí),圍封使不同封育年限的土壤pH值降低。3.荒漠草原采取圍封措施以后,土壤有機(jī)碳含量、全氮含量和全磷含量均高于未圍封樣地,且隨著圍封時(shí)間的變化表現(xiàn)出相似的變化規(guī)律,即：圍封12年時(shí),含量最高,之后,含量出現(xiàn)降低的趨勢(shì)。土壤微生物量碳和微生物量氮均高于未圍封樣地,這說明在荒漠草原采取圍封措施可以促進(jìn)土壤微生物的活動(dòng),從而提高微生物量。同時(shí),土壤微生物量C：N比值隨圍封時(shí)間的延長(zhǎng)先增大后減小。4.土壤脲酶活性、土壤蔗糖酶活性、土壤過氧化氫酶活性及土壤堿性磷酸酶活性并未表現(xiàn)出明顯的規(guī)律。土壤酶活性的大小受眾多因素的影響,關(guān)于這一方面的原因,仍需要進(jìn)一步的探討。5.從處于圍欄狀態(tài)下的植物、土壤與微生物之間的關(guān)系來看,彼此間的相互作用可對(duì)草地的恢復(fù)起到一定的改善效果。上述研究結(jié)果表明,寧夏荒漠草原在圍欄封育早期階段,植被恢復(fù)、土壤養(yǎng)分改善效果顯著。植被生產(chǎn)力發(fā)生相應(yīng)的改變,具體表現(xiàn)為在圍封超過12年以后開始出現(xiàn)下降趨勢(shì),而這種規(guī)律同樣適用于土壤養(yǎng)分方面。
[Abstract]:As an important ecological restoration measure, the ecologic effect has been the focus of restoration ecology. As the vegetation soil microbial system C, N and P cycle are interconversion between the ecosystem, the exchange process and pattern of plant soil C, N, P in plant and soil are systematically studied, and the seal is deeply understood. The chemometrics covariant relationship between the components of the system during the restoration of animal husbandry ecological restoration is of great significance to reveal the stability maintenance mechanism of the desert steppe ecosystem. In this study, the desert steppe in Ningxia was taken as the research object. The soil carbon, nitrogen, phosphorus and soil microstructures were compared and analyzed by the comparison and analysis of the unsealed 5,8,12,15 year plots. The change process and law of biomass carbon, nitrogen and soil enzyme activity, and analyze the effects of different enclosure years on plants, soil and soil microbes in desert steppe. The following conclusions are obtained: 1. after enclosure, the growth of plants in the desert steppe is restored to a certain extent in the condition of eliminating grazing interference, mainly as the upper part of the plant. Compared with the aboveground biomass of the grazing land, the aboveground biomass of the enclosed 5,8,12 and 15 year plots showed an increase in the aboveground biomass. The vegetation characteristics, such as height and coverage of plants, also showed a similar change, and the height, coverage and aboveground biomass all increased first and then decreased with the prolongation of the enclosed years. The content of carbon and nitrogen in the upper part of the predominant plant was higher than that in the non enclosed land, and the ratio of the C:P ratio and the ratio of N:P to the superior species of the predominant plant were higher than that in the non enclosed land, and the soil bulk density decreased first and then increased with the enclosing time, while the soil moisture content of soil soil showed the opposite change rule. At the same time, the soil organic carbon content, total nitrogen content and total phosphorus content of soil organic carbon content, total nitrogen content and total phosphorus content were higher than that of non enclosed land after the enclosure measures were adopted in the soil pH value of.3. desert grassland. The amount of soil microbial biomass carbon and microbial biomass nitrogen were higher than that of the non enclosed land, which indicates that the enclosure measures in the desert grassland can promote the activity of soil microbes and increase the microbial biomass. At the same time, the soil microbial biomass C:N ratio increases with the prolongation of the enclosure time and then reduces the activity of soil urease in the soil of.4. and soil. Invertase activity, soil catalase activity and soil alkaline phosphatase activity did not show obvious regularity. The size of soil enzyme activity was influenced by many factors. In this respect, further discussion on the relationship between.5. and the relationship between soil and microorganism and the relationship between soil and microorganism still needed to be further explored. The interaction can improve the restoration of grassland. The results showed that the effect of vegetation recovery was remarkable in the early stage of enclosure of the Ningxia desert grassland, and the effect of soil nutrients was improved. The sample is suitable for soil nutrients.
【學(xué)位授予單位】：寧夏大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：Q948.1

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