摘要
稻田CH_4氧化是CH_4排放的自然调节,受多种因素的影响。中国水稻种植区分布广,不同地区的气候环境条件以及水肥管理措施,都会影响稻田CH_4氧化及碳同位素分馏过程。因此,对比研究不同地区稻田甲烷氧化和同位素分馏规律,甄别其影响因子,有助于进一步认识稻田甲烷氧化规律,也可为稻田温室气体减排调控提供科学依据。文章基于稳定性碳同位素的方法,结合室内好氧培养试验,测定了全国主要水稻产区(四川、湖南、江西、浙江、广东和辽宁)典型稻田土壤的CH_4氧化过程,确定了CH_4氧化碳同位素分馏系数α_(ox),研究了不同稻田土壤在不同水分条件下的CH_4氧化和同位素分馏的差异及规律。结果表明,四川资阳以及湖南宝洞峪的水稻土壤CH_4氧化潜力相对偏低,平均为其他地区土壤的六分之一。同时,不同地区稻田土壤CH_4氧化同位素分流系数(^(13)C)α_(ox)差异较大,且与CH_4氧化潜力呈显著负相关。在85%WHC(soil water holding capacity)和1∶1水土质量比时,相关系数分别为-0.85(P=0.032)和-0.82(P=0.047)。进一步研究发现,土壤CH_4氧化潜力与土壤活性铁含量呈显著正相关,在85%WHC和1∶1水土质量比时,相关系数分别为0.86(P=0.042)和0.90(P=0.035);而αox则与土壤活性铁含量呈显著负相关,85%WHC和1∶1水土质量比时,相关系数均为-0.92(P=0.026)。由以上结果可知,土壤水分和土壤活性铁是影响CH_4氧化潜力和碳同位素分馏的重要因素,而有关其作用机制仍需进一步的研究。
CH4 oxiddation is the natural regulation of CH4 emission in paddy soil.However,the CH4 oxiddation is influenced by many factors.Furthermore,rice planting is widely distributed in China,the differences in the environmental factors（such as the climate） and the field managements,should have impacts on the CH4 oxiddation processes and the stable carbon isotope fractionation of CH4 oxiddation.Hence,studies on the CH4 oxiddation and stable carbon isotope fractionation in paddy soils in different area,and clarify the main influences,are crucial for environmental protection and the global warming,and helpful to improve our knowledge in the principle of CH4 oxiddation in paddy soils.Trough aerobic incubations and stable carbon isotope method,this study investigated the CH4 oxidation potential,CH4 oxidation isotope fractionation and the influencing factors in the paddy soils,which differed dramatically in soil biochemical properties.These soil samples were collected from 6 major rice-producing regions of China,including the Ziyang city in Sichuan,Taoyuan city in Hunan,Yingtan city in Jiangxi,Jiaxing city in Zhejiang,Shenyang city in Liaoning and Leizhou city in Guangdong.Results showed that the CH4 oxidation potential for the soil from Ziyang（Sichuan） and Baodongyu（Hunan） were generally lower（about 1/6） than that for the other four soils.At the same time,the CH4 oxidation（^13C） isotope fractionation factor（αox） differed apparently,and was significantly and negatively correlated to the CH4 oxidation potential,with the correlation being-0.85 and-0.81 when the soil water was 85% WHC and was 1∶1 soil water ratio,respectively.Moreover,the correlation analysis showed that,the CH4 oxidation potential was significantly and positively correlated to the concentration of soil active iron,with the r being 0.86（P = 0.042） and 0.90（P = 0.035） when the soil water was 85% WHC（85% of the soil water holding capacity） and soil-water ratio was 1∶1,respectively.Whereas,the αox was significantly and nag
出处
《生态环境学报》
CSCD
北大核心
2016年第6期927-933,共7页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41601262)
土壤与农业可持续发展国家重点实验室开放基金项目(Y20160037)
