本文關(guān)鍵詞： 土壤甲烷通量 森林類型 時空差異 影響因子　出處：《中南林業(yè)科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：面對越來越嚴(yán)重的環(huán)境問題,在人類急切需要一個好的生存環(huán)境的壓力下,由溫室氣體引起的溫室效應(yīng)典型的環(huán)境問題,一直是我們所關(guān)注的問題。而作為大氣甲烷重要匯,森林土壤甲烷通量及其相關(guān)生態(tài)過程的研究已經(jīng)無疑是全球變化生態(tài)學(xué)研究的熱點和前沿之一,為對亞熱帶森林生態(tài)系統(tǒng)中土壤甲烷通量的研究提供基礎(chǔ)數(shù)據(jù),本文以南嶺典型森林生態(tài)系統(tǒng)中常綠闊葉(EG),針闊混交林(EK),山地矮林(GS)三種主要森林土壤類型為研究對象,利用地理位置的特殊性分為南北坡對森林土壤甲烷進(jìn)行研究,在2014年8月-2015年12月觀測期內(nèi),對土壤CH4通量時空變化進(jìn)行研究,同時利用靜態(tài)箱-氣相色譜法對土壤甲烷通量的影響因子(溫度,濕度等)進(jìn)行分析,結(jié)果表明:南嶺常綠闊葉林,針闊混交林和山地矮林這三種主要森林類型都表現(xiàn)為大氣甲烷匯,土壤甲烷通量年均值排序為常綠闊葉林山地矮林針闊混交林,年均值分別為-4.326ug/m~(-2).h~(-1),-6.025ug/m~(-2).h~(-1)和-15.406ug/m~(-2).h~(-1)。對南嶺研究樣地分為南北坡進(jìn)行研究對比,結(jié)果表明:南坡南嶺和北坡莽山,兩者在土壤甲烷通量變化上存在明顯的時空差異。在季節(jié)變化規(guī)律上,南北坡不同森林土壤甲烷通量整體表現(xiàn)為冬春以排放為主,夏秋以吸收為主的季節(jié)變化規(guī)律,12月-3月森林土壤向大氣排放甲烷,表現(xiàn)為大氣甲烷的源。4月-10月森林土壤吸收甲烷,表現(xiàn)為大氣甲烷的匯,土壤甲烷通量存在明顯季節(jié)差異。在空間格局變化上,南坡和北坡均為表現(xiàn)為大氣甲烷的匯,且總體上北坡森林土壤甲烷吸收能力要大于南嶺森林土壤的甲烷吸收能力。進(jìn)一步對土壤甲烷通量的影響因子進(jìn)行分析,結(jié)果表明:土壤地表溫度對三種主要森林土壤類型的土壤甲烷通量影響顯著(P0.05),但土壤地表溫度并不是影響土壤甲烷通量的主控因子。土壤濕度上對三種主要森林類型土壤甲烷通量影響顯著(P0.05),常綠闊葉林和針闊混交林土壤甲烷與土壤濕度呈現(xiàn)負(fù)相關(guān)影響,山地矮林土壤甲烷與土壤濕度呈現(xiàn)正相關(guān)影響。對土壤有機(jī)質(zhì)進(jìn)行分析,南北坡海拔1300m處常綠闊葉林土壤總碳含量,總磷土壤和總氮含量存在顯著差異(P0.05)。土壤的質(zhì)地因素中,不同森林類型土壤甲烷通量與土壤容重存在顯著差異(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).
【學(xué)位授予單位】：中南林業(yè)科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S714
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本文編號：1480283