摘要
湿地是陆地生态系统的重要组成部分,在陆地碳库和固碳中具有重要作用。全球湿地碳库的稳定对减少土地利用变化引起的温室气体释放及减缓气候变化具有重要意义。以升金湖国家级自然保护区的典型滩地为研究对象,采用静态箱—气相色谱法对土壤CO_2释放通量进行观测和测定,并进一步分析土壤有机碳库的分布,探讨了滩地土壤呼吸动态和碳库稳定性。研究结果表明,升金湖0～20 cm滩地土壤有机碳含量为11.47～22.25 g/kg,有机碳密度为3.78～4.58 kg/m^2,平均有机碳密度为4.11 kg/m^2,土壤CO_2-C释放通量为111.7～499.5mg/(m^2.h);滩地土壤有机碳密度和CO_2-C释放通量高于周边地区的水稻土土壤,且其有机碳稳定系数偏低,这表明升金湖滩地土壤有机碳库自身具有较高的稳定性,这是滩地土壤有机碳保持的一种机制,在气候变暖背景下,滩地土壤有机碳库的脆弱性将增加。
As one of the most important components of terrestrial ecosystems,wetlands play an important role in global carbon storage.The stabilizing wetland carbon pool is of key importance in reducing greenhouse gases from land use changes for climate change.In this study,diurnal dynamics of soil respiration was monitored for continuous 39 hours in an interval of 3 hours on April 23-25,2005 and carbon dioxide emission flux was measured using closed chamber method and carbon dioxide content determined by GC spectroscopy,and the stability of soil organic carbon of a typical beach was studied in Shengjin Lake in the middle reach of Yangtze River,in Anhui province,China.The results showed that content of soil organic carbon for 0-20 cm depth ranged from 11.47 to 22.25 g/kg,the density of soil organic carbon from 3.78 to 4.58 kg/m^2 and the mean was 4.11 kg/m^2,and CO_2flux ranged from 111.7 to 499.5 mg/（m^2·h）.The density of soil organic carbon and emission flux of carbon dioxide of beach soil was higher than those of the surrounding paddy fields.However,organic carbon stability of the beach soil was lower than those reported for natural soils and cropland soils.This implied a potential intrinsic mechanism of carbon storage in the wetland soil studied.However,beach soil respiration was in a very prompt response to changes in temperature with a much higher Q_（10）value compared to those reported for croplands and natural soils,indicating a great vulnerability of soil organic carbon storage under climate warming.This study demonstrated that protection of wetland soils for its great carbon pool is urged for greenhouse gases emission reduction and climate change mitigation under global warming.
出处
《湿地科学》
CSCD
2011年第2期132-139,共8页
Wetland Science
基金
国家自然科学基金重点项目(40830528)资助
关键词
升金湖滩地
土壤呼吸
碳库稳定性
温度敏感性
Shengjin Lake beach
soil respiration
carbon pool stability
temperature dependence
