植被恢复对库布齐沙漠非生长季土壤CH4、N2O通量的影响  

Effects of revegetation on soil effluxes of CH4 and N2O in non-growing season in Hobq Desert,China

作　　者：王博[1] 段玉玺[1] 王伟峰[1] 李晓晶[1] 刘宗奇 刘源 WANG Bo;DUAN Yuxi;WANG Weifeng;LI Xiaojing;LIU Zongqi;LIU Yuan(Inner Mongolia Forestry Research Institute,Hohhot 010010,China)

机构地区：[1]内蒙古自治区林业科学研究院,呼和浩特010010

出　　处：《生态学报》2020年第6期2028-2038,共11页Acta Ecologica Sinica

基　　金：林业科技创新平台项目(2019132021);内蒙古自然科学基金(2017MS0368);国家林业公益性行业科研专项(201404204)。

摘　　要：荒漠土壤温室气体排放是陆地碳氮循环的重要组成部分,目前人工建植促进植被恢复对非生长季荒漠土壤CH4、N2O通量的影响尚不明确。本研究采用静态暗箱-气相色谱和时空替代法,分析非生长季库布齐沙漠东部不同植被恢复阶段土壤CH4、N2O通量特征及其与环境因子之间的关系,探讨植被恢复对非生长季荒漠土壤温室气体排放的影响。结果表明:非生长季荒漠土壤是CH4的吸收汇,也是N2O的排放源。不同植被恢复阶段CH4平均吸收量和N2O排放量均表现为:苔藓结皮固定沙地(47.6μg CH4 m^-2 h^-1,13.5μg N2O m^-2 h^-1)>地衣结皮固定沙地(32.2μg CH4 m^-2 h^-1,9.1μg N2O m^-2 h^-1)>藻结皮固定沙地(23.7μg CH4 m^-2 h^-1,8.7μg N2O m^-2 h^-1)>半固定沙地(22.4μg CH4 m^-2 h^-1,5.0μg N2O m^-2 h^-1)>流动沙地(18.7μg CH4 m^-2 h^-1,3.9μg N2O m^-2 h^-1)。荒漠土壤在不同冻结时期温室气体排放存在较大差异,融冻期CH4吸收贡献率最大,在结冻期N2O排放贡献率最大。非生长季荒漠土壤存在明显的水热同期现象,土壤水热因子对N2O通量的影响较小,仅半固定沙地土壤温度与N2O通量呈显著正相关;而在藻类、地衣和苔藓结皮固定沙地中,土壤温度和含水量均与CH4通量呈显著负相关。植被恢复过程中,生物量的积累和土壤理化性质的改善,能够显著影响荒漠土壤CH4、N2O通量的变化。因此,人工建植促进植被恢复实现沙漠化逆转可改变荒漠生态系统的温室气体排放格局。Greenhouse gas emission from desert soil is an important part of terrestrial carbon and nitrogen cycle,while the influence of artificial vegetation restoration on CH4 and N2O fluxes in desert soil in non-growing seasons is still not clear.In this paper,the static chamber and gas chromatography technique were used.We performed a spatial series analysis that represented at emporalseries to study the desert soil CH4 and N2O fluxes corresponding to the different stages of vegetation restoration during non-growing season.We also explored the correlation of these fluxes with the environmental factors and studied the effects of revegetation on desert soil CH4and N2O fluxes in the eastern Hobq Desert,China.The results showed that the desert soil was a sink of CH4 and a contributor to N2O emission during non-growing season.The change trend for CH4 and N2O fluxes at different restoration stages were the same:moss crust fixed sand(47.6μg CH4 m^-2 h^-1,13.5μg N2O m^-2 h^-1)>lichen crust fixed sand(32.2μg CH4 m^-2 h^-1,9.1μg N2O m^-2 h^-1>algae crust fixed sand(23.7μg CH4 m^ -2 h^-1,8.7μg N2O m^-2 h^-1)>semi-fixed sand(22.4μg CH4 m^-2 h^-1,5.0μg N2O m ^-2 h^-1)>mobile dune(18.7μg CH4 m^-2 h^-1,3.9μg N2O m^-2 h^-1).The greenhouse gas emissions of desert soil in different freezing periods were significantly different.The CH4 absorption contribution rate was the largest in thawing period,while the N2O emission contribution rate was the largest in freezing period.During the non-growing season,there was an obvious hydrothermal synchronization in desert soil.The soil hydrothermal factors had little effect on the N2O flux.Only the soil temperature in semi-fixed sandy land had a significant positive correlation with the N2O flux.But in algae,lichen and moss crust fixed sands,soil temperature and moisture content were all negatively correlated with the CH4 flux.In the process of vegetation restoration,the accumulation of biomass and the improvement of soil physical and chemical properties could significantly affect the chang

关 键 词：荒漠生态系统 非生长季 冻融期 植被恢复 温室气体 

分 类 号：S714[农业科学—林学]