Gully hotspot contribution to landscape methane (CH4) and carbon dioxide (CO2) fluxes in a northern peatland
Gully hotspot contribution to landscape methane (CH4) and carbon dioxide (CO2) fluxes in a northern peatland
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DOI：
10.1016/j.scitotenv.2008.03.015
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发表时间：
2008-10-15
影响因子：
9.8
通讯作者：
Ostle, N.
中科院分区：
文献类型：
--
作者：
McNamara, N. P.;Plant, T.;Ostle, N.
泥炭地是长期的碳集水区，吸收大气中的二氧化碳（CO2）和甲烷（CH4）。在英国的高地上，草甸泥炭地通常存在于以土刺草（Calluna vulgaris， L.）为主的沼地生态系统中。这些景观包含了一系列影响当地水文、气候和植物群落组成的地形特征。在本研究中，我们研究了树状排水沟渠和邻近地层式泥炭的典型植物-土壤系统在生长季节的生态系统CO2呼吸和净CH4通量的变化。沟壑区以禾草、泥炭和混合禾草为主，相邻地层纸泥炭区以绿草为主。总CO2呼吸在Eriophorum spp. (650 +/- 140 Mg CO2 m（-2)h(-1)）区高于Sphagnum spp. (338 +/- 49 Mg CO2 m（-2)h(-1)）、混合草(342 +/- 91 Mg CO2 m（-2)h(-1)）和C. vulgaris (174 +/- 63 Mg CO2 m（-2)h(-1)）区。对净CH4通量的测量表明，与Sphagnurn (0.6 +/- 0.4 mg CH4 m（-2)h(-1)）、混合草(0.1 +/- 0.1 mg CH4 m（-2)h(-1)）和C. uulgaris (0.0 +/- 0.0 mg CH4 m（-2)h(-1)）相比，Eriophorum spp (2.2 +/- 0.6 mg CH4 m（-2)h(-1)）的通量更高。应用GIS方法计算了沟渠对景观尺度温室气体通量的贡献。英国Moor House国家自然保护区的研究结果表明，虽然沟槽只占总陆地面积的9.3%，但沟槽分别占泥炭地净CH4和CO2呼吸通量的95.8%和21.6%。这些发现的含义是，在估算景观尺度泥炭地温室气体通量时，需要考虑特征沟壑区系统的相对贡献。(C) 2008 Elsevier B.V.版权所有
Peatlands are long term carbon catchments that sink atmospheric carbon dioxide (CO2) and source methane (CH4). in the uplands of the United Kingdom ombrotrophic blanket peatlands commonly exist within Calluna vulgaris (L.) dominated moorland ecosystems. These landscapes contain a range of topographical features that influence local hydrology, climate and plant community composition. In this study we examined the variation in ecosystem CO2 respiration and net CH4 fluxes from typical plant-soil systems in dendritic drainage gullies and adjacent blanket peat during the growing season. Typically, Eriophorum spp., Sphagnum spp. and mixed grasses occupied gullies while C. uulgaris dominated in adjacent blanket peat. Gross CO2 respiration was highest in the areas of Eriophorum spp. (650 +/- 140 Mg CO2 m(-2)h(-1)) compared to those with Sphagnum spp. (338 +/- 49 mg CO2 m(-2)h(-1)), mixed grasses (342 +/- 91 mg CO2 m(-2) h(-1)) and C. vulgaris (174 +/- 63 mg CO2 m(-2) h(-1)). Measurements of the net CH4 flux showed higher fluxes from the Eriophorum spp (2.2 +/- 0.6 mg CH4 m(-2) h(-1)) locations compared to the Sphagnurn spp. (0.6 +/- 0.4 mg CH4 m(-2) h(-1)), mixed grasses (0.1 +/- 0.1 mg CH4 m(-2) h(-1)) and a negligible flux detected from C. uulgaris (0.0 +/- 0.0 mg CH4 m(-2)h(-1)) locations. A GIS approachwas applied to calculate the contribution of gullies to landscape scale greenhouse gas fluxes. Findings from the Moor House National Nature Reserve in the UK showed that although gullies occupied only 9.3% of the total land surface, gullies accounted for 95.8% and 21.6% of the peatland net CH4 and CO2 respiratory fluxes, respectively. The implication of these findings is that the relative contribution of characteristic gully systems need to be considered in estimates of landscape scale peatland greenhouse gas fluxes. (C) 2008 Elsevier B.V. All rights reserved.