FLUX TO THE ATMOSPHERE OF CH4 AND CO2 FROM WETLAND PONDS ON THE HUDSON-BAY LOWLANDS (HBLS)
FLUX TO THE ATMOSPHERE OF CH4 AND CO2 FROM WETLAND PONDS ON THE HUDSON-BAY LOWLANDS (HBLS)
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DOI：
10.1029/93jd03020
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发表时间：
1994-01-20
影响因子：
4.4
通讯作者：
ROULET, NT
中科院分区：
文献类型：
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作者：
HAMILTON, JD;KELLY, CA;ROULET, NT
哈德逊湾低地泥炭地池塘是一个复杂的生态系统，其中CH 4和CO2的大气通量受物理和生物因素的共同控制。这导致了溶解气体浓度和大气中气体通量的强烈昼夜变化，需要24小时频繁采样，以准确估计每日通量。在HBL的三个站点的池塘是恒定的净源CH 4和CO2的大气中，在110-180毫克CH 4 m（-2）d（-1）和3700- 11，000毫克CO2 m（-2）d（-1）的平均速率。利率在8月和9月达到峰值。对于CH 4的池塘通量是3-30倍高于邻近的植被表面。对于CO2的净池塘通量的大小相似的植被通量，但通量的方向是相反的，朝向大气。尽管池塘只占HBL面积的8-12%，但它们占其大气CH 4总通量的30%。有一些间接证据表明，池塘是由底层害虫的分解形成的，这种分解是由生长在泥炭-水界面垫上的N-2固定蓝藻的活性刺激的。事实上，从池塘的气体通量是如此不同，从周围的植被表面意味着任何变化的比例，池塘植被面积，可能会发生在应对气候变化，将影响总HBL通量。
Ponds on peatlands of the Hudson Bay lowlands (HBLs) are complex ecosystems in which the fluxes to the atmosphere of CH4 and CO2 were controlled by interacting physical and biological factors. This resulted in strong diel variations of both dissolved gas concentrations and gas fluxes to the atmosphere, necessitating frequent sampling on a 24-hour schedule to enable accurate estimates of daily fluxes. Ponds at three sites on the HBL were constant net sources CH4 and CO2 to the atmosphere at mean rates of 110-180 mg CH4 m(-2) d(-1) and 3700-11,000 mg CO2 m(-2) d(-1). Rates peaked in August and September. For CH4 the pond fluxes were 3-30 times higher than adjacent vegetated surfaces. For CO2 the net pond fluxes were similar in magnitude to the vegetated fluxes but the direction of the flux was opposite, toward atmosphere. Even though ponds cover only 8-12% of the HBL area, they accounted for 30% of its total CH4 flux to the atmosphere. There is some circumstantial evidence that the ponds are being formed by decomposition of the underlying pest and that this decomposition is being stimulated by the activity of N-2 fixing cyanobacteria that grow in mats at the peat-water interface. The fact that the gas fluxes from the ponds were so different from the surrounding vegetated surfaces means that any change in the ratio of pond to vegetated area, as may occur in response to climate change, would affect the total HBL fluxes.