Natural pipes in blanket peatlands: major point sources for the release of carbon to the aquatic system
Natural pipes in blanket peatlands: major point sources for the release of carbon to the aquatic system
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DOI：
10.1111/gcb.12004
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发表时间：
2012-12-01
影响因子：
11.6
通讯作者：
Chapman, Pippa J.
中科院分区：
文献类型：
--
作者：
Holden, Joseph;Smart, Richard P.;Chapman, Pippa J.
天然土壤管道，已被广泛报道在泥炭地，已被证明有助于显着的总流量。在这里，使用测量从八个管道出口，我们认为在17.4公顷的毯泥炭覆盖的集水区内的河流碳的运输天然管道的作用。溶解和颗粒有机碳（DOC和POC）的浓度从管沃茨之间的管道和随着时间的推移变化很大，DOC和0.08和220毫克L-1的POC之间的5.3和180.6毫克L-1。管道是泥炭地河流碳输出的重要途径，单个管道的通量在0.6和67.8千克/年（DOC）和0.1和14.4千克/年（POC）之间变化。管道DOC通量相当于河流出口DOC年通量的20%，而管道POC通量相当于河流POC年通量的56%。不同形态的水碳占总水碳通量的比例在各管道之间变化，DOC在80.0%~ 91.2%之间，POC在3.6%~ 17.1%之间，溶解CO2-C在2.4%~ 11.1%之间，溶解CH 4-C在0.004%~ 1.3%之间。按比例放大到研究集水区所有管道出口的溶解CO2-C和CH 4-C总通量估计分别为89.4和3.6 kg yr（-1）。总体而言，管道出口产生的排放量相当于流中排放量的14%，但提供的水生碳量相当于集水区出口水生碳通量的22%。众所周知，当泥炭受到排水或干燥的影响时，毯状泥炭地的管道密度会增加。因此，在许多泥炭地的环境变化可能会导致从天然管道的水生碳通量的增加，从而影响泥炭地的碳平衡和下游生态过程。
Natural soil pipes, which have been widely reported in peatlands, have been shown to contribute significantly to total stream flow. Here, using measurements from eight pipe outlets, we consider the role of natural pipes in the transport of fluvial carbon within a 17.4-ha blanket-peat-covered catchment. Concentrations of dissolved and particulate organic carbon (DOC and POC) from pipe waters varied greatly between pipes and over time, ranging between 5.3 and 180.6 mg L-1 for DOC and 0.08 and 220 mg L-1 for POC. Pipes were important pathways for peatland fluvial carbon export, with fluxes varying between 0.6 and 67.8 kg yr(-1) (DOC) and 0.1 and 14.4 kg yr(-1) (POC) for individual pipes. Pipe DOC flux was equivalent to 20% of the annual DOC flux from the stream outlet while the POC flux from pipes was equivalent to 56% of the annual stream POC flux. The proportion of different forms of aquatic carbon to total aquatic carbon flux varied between pipes, with DOC ranging between 80.0% and 91.2%, POC from 3.6% to 17.1%, dissolved CO2-C from 2.4% to 11.1% and dissolved CH4-C from 0.004% to 1.3%. The total flux of dissolved CO2-C and CH4-C scaled up to all pipe outlets in the study catchment was estimated to be 89.4 and 3.6 kg yr(-1) respectively. Overall, pipe outlets produced discharge equivalent to 14% of the discharge in the stream but delivered an amount of aquatic carbon equivalent to 22% of the aquatic carbon flux at the catchment outlet. Pipe densities in blanket peatlands are known to increase when peat is affected by drainage or drying. Hence, environmental change in many peatlands may lead to an increase in aquatic carbon fluxes from natural pipes, thereby influencing the peatland carbon balance and downstream ecological processes.