扎龙湿地5月份水-气界面CO2通量

CO_2 Flux across Water-air Interface in Zhalong Wetlands in Spring

为揭示扎龙湿地5月份水—气界面的CO2通量特征,分析环境因子对CO2通量的影响,试验采用静态箱—气相色谱法于2008年5月对扎龙湿地内的典型水体:扎龙湖、龙湖、克钦湖和东升水库水—气界面的CO2通量进行了测定。结果表明:扎龙湖、龙湖、克钦湖和东升水库CO2通量分别为13.57±3.45、17.86±1.80、18.48±0.83和(18.32±3.59)mg.m-2.h-1,平均为16.79mg.m-2.h-1,与北方温带湖泊水库排放通量相近,但明显低于亚热带和热带地区的湖泊水库。扎龙湿地5月份水生态系统通过水—气界面向大气排放CO2,属于CO2的源。相关分析表明,温度(水温和气温)、水生植物生物量(湿质量和干质量)与水体CO2通量呈显著相关,说明温度和水生植物生物量是引起扎龙湿地内湖泊水库春季水—气界面CO2通量空间差异的主要驱动力;总氮(TN)、总磷(TP)与各采样点CO2通量的相关性不显著。

Static chamber/gas chromatogram methods were used to measure CO2 flux across water-air interface in Zhalong Lake, Long Lake, Keqin Lake and Dongsheng Reservoir in Zhalong wetlands in May 2008, aiming to study CO2 flux characteristics and effects of environmental factors on CO2 flux. Results indicated that CO2 flux of Zhalong Lake, Long Lake, Keqin Lake and Dongsheng Reservoir were 13.57± 3.45, 17.86 ±1. 80, 18.48±0.83, and （ 18.32± 3.59 ） mg · m^-2 h^-1 , respectively, and the mean flux was （16.79 ±2.55） mg · m^-2· h^-1 , which was close to the CO2 flux of lakes and reservoirs in temperate zone, but lower than those of lakes and reservoirs in subtropical and tropical zones. Representative water bodies ＂in Zhalong wetlands emit CO2 to atmosphere across water-air interface in spring, which are CO2 sources. A positive correlation between temperature （water temperature and air temperature） and CO2 flux （p 〈 0.05 ） and a negative correlation between aquatic plant biomass （wet weight and dry weight） and CO2 flux （p 〈 0.05 ） were observed, indicating that temperature and aquatic plant biomass were the main driving forces to cause spatial variations in CO2 fluxes of the lakes and reservoirs in Zhalong wetlands in spring. No correlation between total nitrogen, total phosphorus and CO2 flux （p 〉 0.05） was observed.