南岭三种主要森林类型土壤甲烷通量研究

发布时间：2018-01-31 23:29

  本文关键词： 土壤甲烷通量 森林类型 时空差异 影响因子　出处：《中南林业科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：面对越来越严重的环境问题,在人类急切需要一个好的生存环境的压力下,由温室气体引起的温室效应典型的环境问题,一直是我们所关注的问题。而作为大气甲烷重要汇,森林土壤甲烷通量及其相关生态过程的研究已经无疑是全球变化生态学研究的热点和前沿之一,为对亚热带森林生态系统中土壤甲烷通量的研究提供基础数据,本文以南岭典型森林生态系统中常绿阔叶(EG),针阔混交林(EK),山地矮林(GS)三种主要森林土壤类型为研究对象,利用地理位置的特殊性分为南北坡对森林土壤甲烷进行研究,在2014年8月-2015年12月观测期内,对土壤CH4通量时空变化进行研究,同时利用静态箱-气相色谱法对土壤甲烷通量的影响因子(温度,湿度等)进行分析,结果表明:南岭常绿阔叶林,针阔混交林和山地矮林这三种主要森林类型都表现为大气甲烷汇,土壤甲烷通量年均值排序为常绿阔叶林山地矮林针阔混交林,年均值分别为-4.326ug/m~(-2).h~(-1),-6.025ug/m~(-2).h~(-1)和-15.406ug/m~(-2).h~(-1)。对南岭研究样地分为南北坡进行研究对比,结果表明:南坡南岭和北坡莽山,两者在土壤甲烷通量变化上存在明显的时空差异。在季节变化规律上,南北坡不同森林土壤甲烷通量整体表现为冬春以排放为主,夏秋以吸收为主的季节变化规律,12月-3月森林土壤向大气排放甲烷,表现为大气甲烷的源。4月-10月森林土壤吸收甲烷,表现为大气甲烷的汇,土壤甲烷通量存在明显季节差异。在空间格局变化上,南坡和北坡均为表现为大气甲烷的汇,且总体上北坡森林土壤甲烷吸收能力要大于南岭森林土壤的甲烷吸收能力。进一步对土壤甲烷通量的影响因子进行分析,结果表明:土壤地表温度对三种主要森林土壤类型的土壤甲烷通量影响显著(P0.05),但土壤地表温度并不是影响土壤甲烷通量的主控因子。土壤湿度上对三种主要森林类型土壤甲烷通量影响显著(P0.05),常绿阔叶林和针阔混交林土壤甲烷与土壤湿度呈现负相关影响,山地矮林土壤甲烷与土壤湿度呈现正相关影响。对土壤有机质进行分析,南北坡海拔1300m处常绿阔叶林土壤总碳含量,总磷土壤和总氮含量存在显著差异(P0.05)。土壤的质地因素中,不同森林类型土壤甲烷通量与土壤容重存在显著差异(P0.05)。
[Abstract]:In the face of more and more serious environmental problems, under the pressure of human being urgently need a good living environment, Greenhouse Effect caused by greenhouse gases is a typical environmental problem. As an important sink of atmospheric methane, the study of forest soil methane flux and its related ecological processes is undoubtedly one of the hot spots and frontiers of global change ecology. In order to provide basic data for the study of soil methane fluxes in subtropical forest ecosystems, the evergreen broadleaved ebony (EK) and mixed coniferous and broadleaved forests (EK) in typical forest ecosystems of Nanling were used in this paper. Three main types of forest soil were used as the research object, and the forest soil methane was studied on the north and south slopes by using the particularity of geographical location. During the observation period from August 2014 to December 2015, the temporal and spatial variation of soil CH4 flux was studied, and the influence factor (temperature) of soil methane flux (temperature) was studied by static chamber gas chromatography. The results showed that the three main forest types of Nanling evergreen broad-leaved forest, coniferous broad-leaved forest and mountain dwarf forest were atmospheric methane sink. The order of annual mean of soil methane flux is evergreen broad-leaved mountain dwarf forest mixed coniferous and broad-leaved forest, the annual mean value is -4.326ug-1 / mc-1, respectively. -6.025ugr / mng-1) and -15.406ug- / mr-1 respectively. The Nanling study area was divided into north and south slopes. The results showed that there were significant temporal and spatial differences in soil methane fluxes between the Nanling Mountains on the south slope and the mountain on the north slope, and the seasonal variations were also observed. The methane fluxes of different forest soils in North and South Slope showed the seasonal variation of emission mainly in winter and spring, and absorption in summer and autumn. From December to March, forest soil emitted methane into the atmosphere. From April to October, the forest soil absorbed methane, which was the sink of atmospheric methane, and the soil methane flux had obvious seasonal differences. Both the south slope and the north slope are the sink of atmospheric methane, and on the whole, the methane absorption capacity of forest soil on the north slope is larger than that of the forest soil in Nanling, and the influencing factors of soil methane flux are further analyzed. The results showed that the effect of soil surface temperature on soil methane flux of three main forest soil types was significant (P0.05). However, soil surface temperature was not the main factor affecting soil methane fluxes. Soil moisture had a significant effect on soil methane fluxes of three main forest types (P0.05). There was a negative correlation between soil methane and soil moisture in evergreen broadleaved forest and coniferous broadleaved mixed forest, and a positive correlation between soil methane and soil moisture in mountain dwarf forest. The soil total carbon content, total phosphorus soil and total nitrogen content of evergreen broadleaved forest were significantly different from each other at the elevation of 1300 m in the north and south slope. There were significant differences in soil methane flux and soil bulk density between different forest types (P0.05N).
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714
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本文编号：1480283