长江中游湖泊湿地不同植被类型的甲烷排放和植物传输能力  

Methane emission and plant transport capacity of different vegetation types in lake wetlands in the middle reaches of the Yangtze River

作　　者：周文昌[1,2] 许秀环 向珊珊[1,2] 欧文慧 史玉虎[1,2] 杨佳伟 付甜 左艳霞[3] ZHOU Wenchang;XU Xiuhuan;XIANG Shanshan;OU Wenhui;SHI Yuhu;YANG Jiawei;FU Tian;ZUO Yanxia(Hubei Academy of Forestry,Wuhan 430075,China;Hubei Honghu National Wetland Ecosystem Research Station,Honghu 433200,Hubei,China;Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]湖北省林业科学研究院,武汉430075 [2]湖北洪湖湿地生态系统国家定位观测研究站,湖北洪湖433200 [3]中国科学院水生生物研究所,武汉430072

出　　处：《生态学杂志》2024年第12期3726-3734,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31971474)资助。

摘　　要：湖泊湿地是大气甲烷(CH_(4))排放的重要源,然而不同植被类型和植物入侵对湖泊湿地CH_(4)排放和传输CH_(4)的影响研究尚有不足。本研究以长江中游洪湖湿地为对象,建立开阔水域(KK)、浮水植物欧菱(OL)、挺水植物菰(G)和入侵植物凤眼莲(FYL)4个野外试验区,在2022年5—10月,通过漂浮暗箱⁃气相色谱法研究湖泊湿地CH_(4)排放规律和调控因子。结果表明:洪湖湿地CH_(4)排放通量存在明显时间变化,在夏季或秋季期间出现峰值,CH_(4)排放通量范围位于0.10~136.12 mg·m^(-2)·h^(-1)。KK、OL、G和FYL区的CH_(4)排放通量均值分别为1.68、4.52、4.58和28.59 mg·m^(-2)·h^(-1),湖滨带植被区CH_(4)排放通量是开阔水域的2.7~17倍;凤眼莲入侵区CH_(4)排放通量高于其他3个试验区,分别是G、OL和KK的6.2、6.3和17倍,这可能与凤眼莲植物生物量、植物传输CH_(4)和土壤有机碳含量较高有关。此外,3种植被类型G、OL和FYL在8和9月单株植物体传输CH_(4)均值分别为0.02、0.23和0.25 mg·m^(-2)·h^(-1),显示凤眼莲植物体传输量最高。本研究表明,外来植物凤眼莲入侵加强了长江中游湖泊湿地CH_(4)排放,可能对气候变化形成正反馈。Lakes are an important source of atmospheric methane(CH_(4)).However,the impacts of plant types and alien plant invasion on CH_(4)emissions in lakes are insufficiently investigated.In this study,four sites including open water,floating plant(Trapa natans),emergent plant(Zizania latifolia),and invasive plant(Eichhornia crassipes)regions were selected in the Honghu Lake in the middle reaches of the Yangtze River.The concentration of CH_(4)was measured using a floating chamber and gas chromatography method from May to October,2022.There were temporal variations of CH_(4)emission fluxes at the four sites.The CH_(4)emission fluxes ranged from 0.10 to 136.12 mg·m^(-2)·h^(-1),with the peak values presenting in summer or autumn.The mean CH_(4)emission fluxes were 1.68,4.52,4.58,and 28.59 mg·m^(-2)·h^(-1)at the open water,floating plant,emergent plant,and invasive plant sites,respectively.The CH_(4)emission fluxes of three sites with plants were 2.7 to 17 times than that of the open water.The CH_(4)emission fluxes from the site with invasive plant was 6.2,6.3,and 17 times that of the emergent plant,floating plant,and open water sites,respectively.These results could be attributed to the massive plant bio⁃mass,more effective plant⁃mediated transport of CH_(4),and higher soil organic carbon content in the invasive plant site.The plantmediated transport of CH_(4)at the three sites dominated by Zizania latifolia,Trapa natans,and Eichhornia crassipes were 0.02,0.23,and 0.25 mg·m^(-2)·h^(-1),respectively,indicating that Eichhornia crassipes was most efficient in CH_(4)transport.Our results suggest that CH_(4)emission fluxes derived from the invasive plants would be strengthened in the Honghu Lake in the middle reaches of the Yangtze River,which could be a positive feedback on climate change.

关 键 词：湖泊湿地 甲烷排放 植被类型 植物入侵 

分 类 号：Q948[生物学—植物学] X14[环境科学与工程—环境科学]