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Effect Analysis Of Soil Physical And Chemical Properties On N2O Flux In Three Typical Forest Types At Huoditang Forest Region In Qinling Mountain

Posted on:2017-09-29Degree:MasterType:Thesis
Country:ChinaCandidate:H WangFull Text:PDF
GTID:2370330485478671Subject:Forestry
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N2O is an important greenhouse gas,it has a strong warming effect,and the residence time in the atmosphere is also quite long.N2O can not only damage the ozone layer,but also global warming.Qinling as an important geographical dividing line between north and south is particularly evident difference ecosystems,forest ecosystems Qinling unique climate and rich vegetation types,for the study of forest ecosystems N2O flux in response to global change provides an ideal test system.This study selected Qinling three typical forest ecosystems as a research object,continuous observation of a year,using a static chamber-gas chromatographic analysis of changes in soil N2O gas concentration,while observing the impact of the gas concentration changing environmental factors control different ecological forest variation N2O gas system and its influencing factors,to provide data for the construction of forest greenhouse gases change our country.The main findings are as follows:1.Variation of the soil N2O fluxThree Forests in,N2O emission flux in forest of Quercus is 0.0730 mg N2O m-2h-1;N2O emissions flux pine oil is 0.0302 mg N2O m-2h-1;Huashan Forestry N2O in fluxes of 0.0331 mg N2O m-2h-1.Sharptooth oak forest type,the maximum value of N2O emissions occurred in August 2014,N2O emission flux is 0.1813 mg N2O m-2h-1;and in the oil and sharp teeth pine oak forest,the maximum emission values respectively appeared in June 2015 and July2015,emissions were 0.1040 mg N2O m-2h-1 and 0.1505 mg N2O m-2h-1.Three Forests maximum absorption values are present in the winter around January.Overall,three different forest types showed significant seasonal variation characteristics in summer mainly for N2O emissions,and winter cold season is manifested in the absorption of N2O.2.The relationship between soil temperature and soil N2O fluxTemperature is an important factor restricting emissions of nitrous oxide seasonal changes,this study found that the presence of N2O significant temperature effect,have a significant linear relationship between the three forest types and soil N2O flux and soil temperature 5cm and 10 cm,positive correlation.With increasing temperature,soil N2Oemission flux also increased.3.The relationship between soil pore water filling rate?WFPS?and soil N2O fluxThree Forests in having a strong correlation between soil WFPS Huashan pine and pine oil and soil N2O flux,fitting quadratic polynomial equation,when Huashan pine and pine forest in the WFPS were 60.41% and 44.28 %,the type of forest where N2O flux has its maximum value.And there is no obvious correlation between the forest of Quercus soil WFPS and N2O flux.4.The relationship between soil inorganic nitrogen and soil N2O fluxExhibited between the three forest types and soil nitrate content in soil N2O flux significant negative linear correlation?P <0.05?,with the increase of soil nitrate content,N2O fluxes showed a decreasing trend.R2 variation range of between 0.2670.520.Soil ammonium nitrogen content of the performance,there are between Mountain pine forest of Quercus and ammonium nitrogen content of N2O flux weak correlation between Huashan pine and oak forest R2 sharptooth 0.245 and 0.229,respectively,both with significantly increased soil ammonium nitrogen content,N2O emission fluxes were exhibited slight increase.However,pine oil correlation is not obvious,there is no good fitting effect.
Keywords/Search Tags:N2O flux, Qinling mountain, Typical forest types, Environmental Factors, Soil properties
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