放牧对若尔盖高原湿地CH4排放的影响  

Effects of grazing on the emission of CH_4 flux in the Zoige Plateau wetland

作　　者：周文昌[1,2] 崔丽娟[1] 王义飞[1] 李伟[1] 

机构地区：[1]中国林业科学研究院湿地研究所,湿地生态功能与恢复北京市重点实验室,北京100091 [2]湖北省林业科学研究院,武汉430075

出　　处：《生态学报》2017年第3期851-859,共9页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201204201,201304315);国家林业局“948”项目(2014-4-67);国家科技支撑项目(2011BAC02B03)

摘　　要：湿地是大气甲烷(CH_4)的主要排放源,而有关放牧对湿地CH_4排放的影响特征仍未得到足够的报道。因此,通过静态箱法,研究了放牧对四川省若尔盖高原湿地CH_4排放的影响,CH_4气体通过快速温室气体分析仪测量。结果表明:放牧样地和围栏内样地生长季CH_4排放量为(31.32±19.57)g/m^2和(30.31±23.46)g/m^2,它们之间无差异显著;但是集中放牧期间(7—9月),放牧样地(21.01±12.35)g/m^2较围栏内样地显著增加了CH_4排放量为54.3%。2014年生长季期间通过刈割植物模拟放牧表明两种刈割强度CH_4排放量为(5.01±5.37)g/m^2和(4.69±5.99)g/m^2,较未刈割样地(1.15±1.89)g/m^2增加了335.9%和308.0%,其原因可能是放牧或者刈割减少地表植物生物量,降低植物高度,缩短了CH_4排放的路径距离。该结果可为我国高原湿地保护与管理决策提供基础数据支撑。Wetland ecosystems, as the main source of atmospheric methane （ CH4） , could seriously affect the concentration of atmospheric CH4 and further climate change. Presently, wetland ecosystems have been severely affected by human actives （i.e., drainage, grazing, and harvesting）. However, the effects of grazing on the CH4 emission of wetland ecosystems have not been well investigated. Therefore, to evaluate the effects of grazing on the emission of CH4 flUX, we performed the field experiments in the Zoige Plateau wetland, southwestern China, from June to October 2013. We also performed field experiments to investigate the effects of simulated increased in sheep or yak grazing by the clipping on CH4 emission in the same studied sites from May to October 2014. CH4 emission was measured using a dark static chamber and the fast greenhouse gas analyzer （FGGA） during the two growing season. We observed an obvious seasonal variation in CH4 emission at the studied sites. The CH4 emission varied from -0.42 to 18.06 mg m-2 h-2 and its maximum value occurring in summer and/or autumn. These results showed that the cn4 emission in the grazing and fencing plot was （31.32± 19.57） g/mE and （30.31±23.46） g/m2, respectively, during the growing season, and there were no significant differences in cn4 emission between grazing and fencing plots （P〉0.05）.However, the CH4 emission in the grazing plot was （21.01±12.35） g/m： during heavy grazing periods （from July to September 2013）, which was 54.3% higher than that in the fencing plot （ungrazed plot）. Moreover, the results revealed that the CH4 emission in the two clipping plots with 8 cm and 4 cm of vegetation height after clipping were （5.01±5.37） g/m2 and （4.69±5.99） g/m2, respectively, during the growing season, which were significantly higher in the 8 cm vegetation height in the clipping plot （335.9%） than that in the non-clipping plot （1.15±1.89） g/m2（P〈0.05）, and 308.0% higher in the 4 cm vegetation height in the cli

关 键 词：放牧 刈割 CH4排放 若尔盖高原湿地 

分 类 号：S811.5[农业科学—畜牧学]