The Effect Of Climate Change On Greenhouse Gas Emissions In An Alpine Meadowon The Zoige Plateau

Fluctuations in greenhouse gas?GHG?concentrations in the atmosphere can lead to profound climatic and environmental changes,climate change is one of the major problems facing the human.The change of temperature and precipitation are two of the most obvious feature of it.The Tibetan plateau as a sensitive and fragile area,the release of GHG such as carbon dioxide?CO₂?,meathane?CH₄?,And nitrous oxide?N₂O?from alpine ecosystems has been the focus of biogeochemical research due to its great potential contribution to feedbacks to global warming.This study was conducted on an alpine meadow ecosystem from August,2015 to July 2016 at the Zoige Plateau of alpine meadow ecosystem.We aimed to explore the responses of greenhouse gases fluxes to climatic change through examining the greenhouse gases fluxes under warming and precipitation changing.The main results were summarized as follows:1?Warming treatment: temperature has a significant effect on the flux of carbon dioxide and methane in 4 months?August,2015.MaytoJuly,2016?ofgrowing season;Compared with control,warming treatment can improve 36.7% ecosystem respiration emission flux singnificantly,the average flux of control is 400.28±92.32mg·m^-2h^-1,and the warming treatment is 547.08±111.19mg·m^-2h^-1;warming treatment can singnificantly improve 40.0% methane flux in this time,the average flux of control is-3.26±0.32?g·m^-2h^-1,and the warming treatment is-4.57±0.64?g·m^-2h^-1.2?Precipitation treatment:Precipitation change has a significant effect on the flux of carbon dioxide methane and nitrous oxide in 4 months?August,2015.May to July,2016?of growing season;Compared with control,half of precipitation can reduce 12.3% ecosystem respiration emission flux singnificantly,the average flux of control is 430.47±42.28mg·m^-2h^-1,and thetreatment is 377.55±48.2mg·m^-2h^-1;half of precipitation can singnificantly reduce 59.5% methane flux in this time,the average flux of control is-3.63±0.67?g·m^-2h^-1,and the warming treatment is-5.8±1.5?g·m^-2h^-1.also half of precipitation can singnificantly reduce 28.8% nitrous oxide flux in this time,the average flux of control is 0.22±0.03?g·m^-2h^-1,and the warming treatment is 0.16±0.04?g·m^-2h^-1.quarter of precipitation has no significant on the flux of carbon dioxide methane,but can extremely singnificantly reduce 59.7% nitrous oxide flux,the average flux is 0.09±0.05?g·m^-2h^-1.3?Non-growing season:In non-growing season?October,2015 to April 2016?,the the flux of carbon dioxide methane and nitrous oxide are very different,the flux of N₂ O is the largest proportion among annual of CO₂,CH₄ and N₂ O,the flux is 66.67%.the N₂ O flux of april consist 19% proportion for N₂ O all flux of non-growing season.CO₂ flux of non-growing season consist 20% proportion for CO₂ annual flux,april flux consist 17% proportion for CO₂ flux of non-growing season,the proportion of CH₄ is 56.71%?annual?and 20%?non-growing season?.4?The correlation of GHG fluxes with environmental factors:From April to July of 2016,ecosystem respiration emission flux is very significant positive correlation with the temperature at 10 cm soil layer.CH₄ flux is significant negative correlation with the temperature at 5cm soil layer and very significant negative correlation with 10 cm.In non-growing season,CO₂ flux is significant positive correlation with the air temperature and temperature at 5cm soil layer.N₂ O flux is very significant positive correlation with relative humidity.