三江平原垦殖湿地恢复对温室气体排放的影响  

Impacts of reclamation marsh restoration on greenhouse gas emission in the Sanjiang Plain,China

作　　者：赵月琴 马秀静 赵琬婧 张治军 孙晓新[1,3] ZHAO Yueqin;MA Xiujing;ZHAO Wanjing;ZHANG Zhijun;SUN Xiaoxin(Ministry of Education Key Laboratory of Sustainable Forest Ecosystem Management,School of Forestry,Northeast Forestry University,Harbin 150040,China;Heilongjiang Sanjiang National Nature Reserve Administration,Fuyuan 156500,Heilongjiang,China;Heilongjiang Sanjiang Plain Wetland Ecosystem Research Station,Fuyuan 156500,Heilongjiang,China)

机构地区：[1]东北林业大学林学院,森林生态系统可持续管理教育部重点实验室,哈尔滨150040 [2]黑龙江三江国家级自然保护区管理局,黑龙江抚远156500 [3]黑龙江三江平原湿地生态系统国家定位观测研究站,黑龙江抚远156500

出　　处：《应用生态学报》2023年第8期2142-2152,共11页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金面上项目(31870443);中央高校基本科研业务费项目(2572021DS04)资助。

摘　　要：为揭示三江平原垦殖湿地退耕还湿后湿地生态系统温室气体通量的变化规律,本研究选取自然恢复的退耕4、7、11、16、20年沼泽湿地为对象,以未退耕地(开垦13年的大豆田)和未开垦的天然大叶章-臌囊苔草沼泽湿地为对照,利用静态暗箱-气相色谱法观测二氧化碳(CO_(2))和甲烷(CH_(4))通量的变化规律,并探讨影响其排放的主要因素。结果表明:不同恢复年限垦殖湿地CO_(2)和CH_(4)生长季通量具有明显的季节变化规律,且随着恢复年限的增加,温室气体的季节变化趋势逐渐与天然沼泽湿地相似。生长季CO_(2)通量均值在恢复前期增加,在恢复后期减少,由893.4 mg·m^(-2)·h^(-1)(恢复4年样地)降至494.0 mg·m^(-2)·h^(-1)(恢复20年样地);CH_(4)通量均值随着恢复年限的增加而增加,由CH_(4)的弱汇(大豆田,-0.6 mg·m^(-2)·h^(-1))增至87.8 mg·m^(-2)·h^(-1)(恢复20年样地),但通量始终低于天然沼泽湿地(96.4 mg·m^(-2)·h^(-1))。相关性分析显示,退耕还湿后样地水位升高和土壤电导率的增加是导致恢复湿地CO_(2)通量均值减少的主要原因;而退耕还湿后样地水位升高、土壤可溶性有机碳增加是导致恢复湿地CH_(4)通量均值增加的主要原因。全球增温潜势随着垦殖湿地恢复年限的增加而增加,由27.8t·CO_(2)-eq·hm-2(大豆田)增至130.8 t·CO_(2)-eq·hm-2(恢复20年样地),并逐渐接近于天然沼泽湿地(156.3 t·CO_(2)-eq·hm-2)。三江平原大豆田退耕还湿后温室气体排放逐渐接近天然沼泽湿地,但恢复后湿地的温室气体排放量多久才能恢复至与天然沼泽湿地相同的水平,还要在更长的时间尺度内进行观测。To understand the variations in greenhouse gas fluxes during the process of returning cropland to wetland in the Sanjiang Plain,we selected naturally restored wetlands of 4,7,11,16 and 20 years as research objects to compare with a cultivated site(soybean plantation for 13 years)and an uncultivated marsh dominated by Deyeuxia purpurea and Carex schmidtii.We measured carbon dioxide(CO_(2))and methane(CH_(4))fluxes using a static chamber-gas chromatography and explored the main influencing factors.The results showed that there were seasonal variations in growing-season CO_(2)and CH_(4)fluxes of the restored wetlands,with the seasonal trends in greenhouse gases becoming gradually similar to that of natural marsh with increasing restoration time.The mean growing-season CO_(2)fluxes increased during the early stage of restoration,but then decreased during the late stage,which decreased from 893.4 mg·m^(-2)·h^(-1)to 494.0 mg·m^(-2)·h^(-1)in the 4-year and 20-year sites,respectively.Mean CH_(4)fluxes increased with restoration time,ranging from a weak CH_(4)sink(soybean fields,-0.6 mg·m^(-2)·h^(-1))to a CH_(4)source of 87.8 mg·m^(-2)·h^(-1)(20-year restored site).The CH_(4)fluxes of experimental plots were consistently lower than that of natural marsh(96.4 mg·m^(-2)·h^(-1)).Increases in water level and soil conductivity resulting from restoration were the main driving factors for the decrease in CO_(2)fluxes.The increases in water level and soil dissolved organic carbon resulting from restoration were the primary drivers for the increase of CH_(4)fluxes in the restored wetlands.The global warming potentials increased with restoration time,ranging from 27.8 t·CO_(2)-eq·hm-2(soybean fields)to 130.8 t·CO_(2)-eq·hm-2(plot of 20-year restoration),which gradually approached that of natural marsh(156.3 t·CO_(2)-eq·hm-2).The emission of GHGs from restored wetlands in the Sanjiang Plain gradually approached those of natural marsh.Further monitoring is required to identify the maturity of restored wetlands for ach

关 键 词：退耕还湿 CO_(2)通量 CH_(4)通量 全球增温潜势 三江平原 

分 类 号：X171.1[环境科学与工程—环境科学]