摘要
为了深入分析环境因子对湿地CH_4排放产生的影响,利用中型试验生态系对若尔盖典型泥炭地开展地下水位和土壤温度控制试验,比较不同条件下泥炭地2012年生长季(5—10月)CH_4排放通量的月变化情况.结果表明:高水位(土壤表面0 cm)下CH_4排放通量最高,中水位(地表以下10 cm)下次之,低水位(地表以下20 cm)下最低;其中,10月CH_4排放通量变化不明显,不同地下水位下泥炭地的CH_4排放通量均在7月达到最大值,并且均呈明显的单峰曲线,高、中、低地下水位下CH_4排放通量平均值分别为6.263 3、4.754 4和3.949 8 mg/(m^2·h).而且,在一定温度范围内,不同地下水位条件下CH_4排放通量随土壤温度的升高均呈指数式增长.其中,高水位下CH_4排放通量对土壤温度变化最为敏感,中水位下次之,低水位下相对最不敏感.研究显示,若尔盖泥炭地CH_4排放通量表现出明显的季节性变化差异,并且季节性升温和涨水均会促进CH_4排放通量的增加.
In order to study the impact of environmental factors on wetland methane（ CH4） emissions,we monitored the water table level and soil temperature in Zoige Peatlands and compared the monthly change of methane emissions during six months of plant growth period at the mesocosm scale from May to October,2012. Three water level scenarios were considered including 0 cm depth,10 cm depth and 20 cm depth（ presented below as W0,W10 and W20,respectively）. The results showed that CH4 emissions increased when water table depths increased from W20 to W10 and W10 to W0 from May to September. There was no significant difference in October. The overall change of CH4 emissions from May to October was a single-peak curve,with maximum flux of CH4 emission being observed in July. The mean CH4 emission fluxes were 6. 2633,4. 7544 and 3. 9498 mg/（ m^2·h） at the water table depths of 0,10 and 20 cm,respectively. In a limited temperature range,CH4 emission fluxes increased exponentially with the increase of soil temperature at various water table depths. The CH4 emission fluxes were most sensitive to soil temperature changes at the water table depths of W0,followed by W10,while CH4 emission fluxes were of the least significance at the water table depths of W20. The results suggest that CH4 emission flux varies with seasons in Zoige Peatlands and that,in general,high water table depth and temperature enhance CH4 emission fluxes.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第4期516-521,共6页
Research of Environmental Sciences
基金
国家自然科学基金项目(41103041)
