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Effects Of Changing Soil Acidity/alkalinity On Soil Nitrogen And Greenhouse Gas Fluxes In A Pinus Tabulaeformis Forest In Taiyue

Posted on:2020-01-02Degree:MasterType:Thesis
Country:ChinaCandidate:H YuFull Text:PDF
GTID:2370330575491972Subject:Ecology
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The burning of fossil fuels and the continuous destruction of human beings into the natural environment have led to the deterioration of the ecological environment and the growing problem of global climate change.As a key component of terrestrial ecosystems,the impact on climate change has received extensive attention.Changes in the forest ecosystem environment directly affect the forest carbon and nitrogen cycle,transformation mechanisms,etc.,thereby jeopardizing the entire terrestrial ecosystem and the atmospheric environment.What are the regular patterns of changes in forest soil nitrogen and soil greenhouse gases under different nitrogen application levels,and whether greenhouse soil greenhouse gas emissions will be affected by soil nitrogen,which is the study of atmospheric nitrogen deposition on forest ecosystem nitrogen.An important knowledge node for the loop.In order to better explore this issue in depth,this study began to acidify the soil of Pinus tabulaeformis forest in May2015:N5(5 g/m2)?N10(10g/m2)?N20(20g/m2)?N40(40 g/m2)concentration of ammonium nitrate,alkali treatment:addition of H50(50g/m2)?H100(100g/m2)?H200(200 g/m2)?H400(400 g/m2)concentration The soda lime,as well as the control treatment(CK),was designed for 4 replicates per treatment.Nitrogen(total nitrogen,total soluble nitrogen,soluble organic nitrogen,ammonium nitrogen,nitrate nitrogen)and greenhouse gas emission fluxes were measured in the growing season.The results show:(1)After the addition of acidic substances,the soil pH decreased,and the 0-10 cm soil layer increased soil total nitrogen,total soluble nitrogen,soluble organic nitrogen,inorganic nitrogen(NH4+-N and NO3--N),and soil microbial biomass nitrogen.In the 10-20 cm soil layer,the contents of total nitrogen,total soluble nitrogen,inorganic nitrogen(NH4+-N and NO3'-N)increased,while the content of soil soluble organic nitrogen and microbial biomass nitrogen decreased.After the addition of alkaline substances,the pH value of soil in 0-10cm soil layer increased,but the contents of total nitrogen,total soluble nitrogen,soluble organic nitrogen,inorganic nitrogen(NH4+-N and N03--N)and microbial biomass nitrogen decreased..In the 10-20 cm soil layer,the contents of total nitrogen and inorganic nitrogen(NH4+-N and NO3--N)increased,while total soluble nitrogen,soluble organic nitrogen and microbial biomass nitrogen decreased.Acidic additives have a significant effect on the nitrogen content of the soil,and the addition of alkaline substances inhibits the nitrogen content and conversion in the soil.(2)The soil acid-base environment significantly changed the nitrogen content in the soil and the conversion efficiency between nitrogen.Acidic treatment promoted soil nitrogen content and nitrogen conversion,and significantly increased nitrogen mineralization efficiency and nitrification in soil,while alkaline substances inhibited soil nitrogen content and nitrogen conversion.effect;(3)The change of soil acid-base environment plays an important role in promoting the emission of greenhouse gases(N2O,CO2,CH4).The higher the concentration of the acidic additive,the higher the emissions compared to the alkaline treated N2O.The addition of alkaline substances promoted the emission of CO2 and CH4 significantly higher than that of acidic treatment.
Keywords/Search Tags:ammonium nitrate, soil acid alkline environment, soil nitrogen, greenhouse gases
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