典型气候/环境因子变化对九段沙湿地碳固定潜力的影响

Effects of Changes of Typical Climate/Environmental Factors on Soil Carbon Sequestration Potential in Jiuduansha Wetland,China

利用人工气候室模拟长江口区域几种典型气候/环境因子的变化特征(全球变暖、CO2增加和海水无机氮污染加剧等),并从植物生长量和土壤呼吸角度综合分析了这些气候/环境因素的变化对九段沙湿地土壤有机碳汇聚能力的影响。初步结果表明,在实验范围内,与对照相比,单方面的温度升高、无机氮污染加剧和CO2浓度升高会提高九段沙土壤的有机碳汇聚能力。无机氮污染加剧协同升温对土壤呼吸有一定的消减作用,从而提高了土壤有机碳汇聚能力;无机氮污染加剧协同CO2浓度升高会促使土壤有机碳的排放,使其碳汇聚能力下降;CO2浓度升高和全球升温的共同作用不会显著降低有机碳汇聚能力;无机氮污染加剧和CO2浓度升高的基础上加入升温的三因素交互作用会促进土壤有机碳的排放,使其碳汇聚能力下降。因此,要尽力避免海水中无机氮污染加剧和CO2浓度升高两个因素,以及在此基础上升温情况的同时发生。

The organic carbon reservation capability in soil has great significance on reduction of the greenhouse gases release and relief of global wanning. With the further global climate wanning, it has gradually attracted more and more attentions on the research of the soil respi- ration and carbon sequestration in coastal salt marsh. Jiuduansha wetland with many important ecological functions is the most impermanent original ecological coast salt marsh ecosystem in the Yangtze River estuary, and its carbon sequestration function is of great significance to the balance of carbon emissions in Shanghai. In this study, the possible effects of the changes of some typical climate/environment factors such as warming, atmospheric CO2 enrichment and inorganic nitrogen addition on soil carbon accumulation ability in Jiuduansha wetland were stud- led.The results showed that both considering of soil respiration and plant biomass, wanning, atmospheric C02 enrichment and inorganic nitro- gen addition, respectively, within certain ranges could increase the soil organic carbon accumulation ability comparing with the control. Wanning combined with inorganic nitrogen addition also could enhance the soil organic carbon accumulation ability. However, atmospheric CO2 enrichment combined with aggravated water eutrophication prompted the issue of soil organic carbon, which ultimately decreased the soil organic carbon accumulation ability. Atmospheric C02 enrichment combined with warming had no significantly effect on soil organic accumu- lation capability of Jiuduansha wetland. Wanning, atmospheric C02 enrichment combined with inorganic nitrogen addition could prompte the issue of soil organic carbon, which ultimately decreased the soil organic carbon accumulation ability. So, the situation of wanning, atmospher- ic C02 enrichment combined with inorganic nitrogen addition should be avoid as far as possible in the further for keeping organic carbon reservation capability of Jiuduansha wetland.