草海高原湿地湖滨带甲烷产生与氧化潜力研究

发布时间：2018-03-20 21:56

本文选题：草海湖滨湿地　切入点：甲烷产生潜力　出处：《贵州师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：甲烷(CH4)是大气中含量仅次于二氧化碳(CO2)的第二大温室气体。在100年时间尺度,单个分子CH4的温室效应比CO2高25倍,而且大气中甲烷的一系列反应还会影响臭氧浓度。大气中甲烷浓度从工业革命前的0.7ppmv增加到当前的1.8ppmv,其年均增幅为0.5%-0.8%。湿地是重要的碳汇,也是温室气体CH4等的排放源,其排放量占CH4自然排放总量的70%,占全球CH4排放总量的24.8%。由于人类活动和气候变化,湿地水文条件发生明显的改变,湿地水位下降。湿地水文条件变化对CH4产生与氧化的影响及其环境调控机制尚无不明确。本文以云贵高原典型湿地草海为研究对象,研究湿地自然水位梯度下CH4产生与氧化潜力的变化规律及其与环境因子的关系,研究结果有助于理解湿地CH4排放的异质性及其机制。本文主要研究结论:(1)草海高原湿地湖滨带甲烷产生潜力的变化规律为农田原生沼泽草甸沼泽草甸;甲烷氧化潜力的变化规律为原生沼泽农田草甸沼泽草甸。(2)草海高原湿地湖滨带甲烷产生与氧化潜力垂直空间变化不同。整体上甲烷产生潜力随土层深度增加而降低,而甲烷氧化潜力随深度的变化差异不显著。湿地甲烷产生潜力最大土层是0-5cm,与其它土层差异显著(p0.05)。(3)草海高原湿地湖滨带甲烷产生潜力季节变化为:秋季春季夏季冬季,甲烷氧化潜力的季节变化为:夏季春季冬季秋季。(4)草海高原湿地湖滨带原生沼泽、沼泽草甸土壤甲烷产生潜力与甲烷氧化潜力呈极显著正相关,草甸甲烷产生潜力与甲烷氧化潜力极显著负相关,农田与其相关性不显著。(5)草海高原湿地湖滨带甲烷产生和氧化潜力与环境因子的关系:土温与农田甲烷产生潜力、原生沼泽甲烷氧化潜力显著正相关;Eh与原生沼泽甲烷产生潜力、沼泽草甸甲烷氧化潜力显著负相关;土壤含水量与沼泽草甸甲烷产生潜力显著正相关,p H与原生沼泽、沼泽草甸甲烷产生潜力显著正相关。(6)草海高原湿地湖滨带甲烷产生和氧化潜力与电子受体的关系:同一种离子对不同阶段湿地甲烷产生和氧化活性的影响存在明显的差异,不同的阴阳离子对不同类型湿地甲烷产生和氧化潜力的影响不同。在阳离子中,二价铁离子、铵根离子对沼泽草甸甲烷产生主要起促进作用,对原生沼泽和草甸甲烷氧化主要起抑制作用;硝酸根离子对原生沼泽甲烷氧化潜力的抑制作用最强;二价锰离子对原生沼泽土壤甲烷氧化具有促进作用。(7)由主成份分析可得,影响草海高原湿地湖滨带甲烷产生和氧化潜力的主要因子是土壤含水量、DOC、NH4-N。但分析的主要因子解释的信息量不高,说明主要影响因素除环境因素、电子受体外,还有微生物、植物根系分泌物等。
[Abstract]:CH4 is the second largest greenhouse gas in the atmosphere after carbon dioxide (CO2). On a 100-year scale, Greenhouse Effect, a single molecule, is 25 times higher than CO2. Moreover, a series of reactions to methane in the atmosphere will also affect ozone concentration. The concentration of methane in the atmosphere has increased from 0.7 ppmv before the industrial revolution to 1.8 ppmv today, with an average annual growth rate of 0.5 to 0.8 percent. Wetlands are an important carbon sink and a source of greenhouse gas CH4 and so on. Its emissions account for 70% of the total natural emissions of CH4 and 24.8% of the total global CH4 emissions. As a result of human activities and climate change, the hydrological conditions of wetlands have changed significantly. The effect of changes of wetland hydrological conditions on CH4 production and oxidation and its environmental regulation mechanism are not clear. This paper takes the typical wetland grass and sea in Yunnan-Guizhou Plateau as the research object. The changes of CH4 production and oxidation potential under natural water level gradient in wetlands and their relationship with environmental factors were studied. The results are helpful to understand the heterogeneity and mechanism of CH4 emission from wetlands. The main conclusions of this paper are as follows: (1) the change of methane production potential in the wetland lakeside zone of the Caohai Plateau is the primary marsh meadow meadow meadow. The variation of methane oxidation potential is different from that of vertical spatial variation of methane oxidation potential in meadow meadow meadow and meadow meadow in grass sea plateau. On the whole, methane production potential decreases with the increase of soil depth. However, there is no significant difference in methane oxidation potential with depth. The maximum soil layer of methane production potential in wetland is 0-5 cm, which is significantly different from other soil layers (p 0.05 ~ (.3)) the seasonal variation of methane production potential in the wetland lakeside zone of the Caohai Plateau is as follows: autumn, spring, summer and winter. The seasonal variation of methane oxidation potential is as follows: summer, spring, winter and autumn. 4) the primary swamp of wetland lakeside zone in the Caohai Plateau. The methane production potential of marsh meadow soil is significantly positively correlated with methane oxidation potential. Meadow methane production potential is negatively correlated with methane oxidation potential, while farmland is not. 5) relationship between methane production and oxidation potential and environmental factors: soil temperature and farmland methane production potential. There was a significant positive correlation between Eh and methane production potential in native marsh, and negative correlation between methane oxidation potential in marsh meadow and soil moisture content and methane production potential in marsh meadow, and significant positive correlation between soil moisture content and methane production potential in marsh meadow. The relationship between methane production and oxidation potential and electron receptor in wetland lakeside zone of the Caohai Plateau: the effects of the same ion on methane production and oxidation activity in different stages of wetland were significantly different. Different anions have different effects on methane production and oxidation potential in different types of wetlands. In cations, iron and ammonium ions play a major role in promoting methane production in marsh meadows. It mainly inhibited the oxidation of methane in marsh and meadow; the nitrate ion had the strongest inhibitory effect on the oxidation potential of methane in the primary swamp; and the bivalent manganese ion could promote the oxidation of methane in the primary marsh soil. The main factor affecting methane production and oxidation potential in the wetland lakeside zone of the Caohai Plateau is the soil moisture content (DOC) NH _ 4-N, but the amount of information explained by the main factors analyzed is not high, which indicates that the main influencing factors are not only environmental factors, but also microbes, in addition to electron receptors. Plant root exudates, etc.
【学位授予单位】：贵州师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X16;X171

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