三江平原不同土地利用方式下湿地土壤CO2通量研究

利用暗箱-气相色谱法,同步测量了三江平原几种主要生态类型湿地土壤原始的小叶章草甸白浆土、毛果苔草泥炭沼泽土、已垦旱作草甸白浆土和人工水田草甸白浆土,进行CO2排放通量的对比研究.结果表明不同土地利用方式下,旱作草甸白浆土土壤CO2排放通量最大,平均值为775.38mg/(m2@h);小叶章草甸白浆土土壤次之,平均值为439.02mg/(m2@h);人工水稻田草甸白浆土土壤CO2通量最小,平均值为128.96mg/(m2@h);毛果苔草泥炭沼泽土土壤CO2排放通量介于小叶章草甸白浆土土壤和水稻田草甸白浆土土壤之间,平均值为247.08mg/(m2@h).湿地开垦为旱田,使湿地"碳汇"功能减弱或丧失,变成"碳源";湿地开垦为水田,是比较合理的湿地农业利用方式.

Study on Soil CO2 Fluxes From Different Land Use Types in the Sanjiang Plain

Marsh-wetland, one important type of wetlands, is a synthetic natural ecosystem, with rich carbon , one third of global carbon is stored in it. Land use change of wetlands could bring on the CO2 fluxes change, and it is said that the CO2 fluxes through land use change are equal to 30% of CO2 through the large scale burning of oil, coal and gas, which power modern industrial economies. So it is basilic significance to study the soil CO2 fluxes change under large-scale land use change. The Sanjiang plain is the largest and most concentrated marsh-wetland region in China, it also a typical place there appears huge land use change during recent 50 years. We selected this region for study, and we focus on the soil CO2 fluxes of the different land use types. The soil CO2 fluxes was measured by closed opaque chamber and gas chromatography (Agilentilent 5890) system. Meanwhile, the inside and outside chamber air temperatures, surface and 5cm, 10cm depth soil temperature were also measured at the same time. The experimental data show that the most CO2 fluxes are from the agriculture dry land as a meadow lessive soil, the second is Calamagrostis angustifolia on meadow lessive soil, and the third is Carex lasiocarpa on peat mire soil, the lowest CO2 fluxes are paddy field on meadow lessive soil except September for solarize. There will be weak the function of carbon sink after wetlands have been reclaimed to dry land and become a carbon source; the paddy field is a wise wetland agriculture utilization.