Landscape controls on riverine export of dissolved organic carbon from Great Britain
Landscape controls on riverine export of dissolved organic carbon from Great Britain
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对英国溶解有机碳河流出口的景观控制
DOI：
10.1007/s10533-021-00762-2
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发表时间：
2021
期刊：
影响因子：
4
通讯作者：
Williamson J
中科院分区：
文献类型：
--
作者：
Williamson J
溶解有机碳（DOC）通过河流从陆地向海洋的输出是全球碳循环中的一个重要环节，并在许多地区受到人类活动的影响。来自全球大型河流的DOC输出量相当好地量化，但来自较小河流系统的DOC输出量，包括那些排放海洋区域的DOC输出量，通常在全球综合中代表性不足。鉴于这些地区通常具有高径流量和高泥炭覆盖，它们可能会对全球陆地-海洋DOC输出产生不成比例的影响。在这里，我们描述了一个全面的新的评估，每年的河流DOC出口到河口的大不列颠岛（GB），跨越纬度范围50-60° N的地形，土壤，降雨，土地利用和人口密度的强烈空间梯度。DOC产量（单位面积出口）呈正相关，最好的预测降雨量，泥炭范围和森林覆盖，但相对不敏感的人口密度或农业发展。根据土地利用和降雨量的经验关系，我们估计2017年从GB陆地区域到淡水-海水界面的DOC输出为1.15 Tg C year-1。GB河流的平均产水量为5.04 g C m− 2 year −1，高于世界上大多数主要河流，包括潮湿热带和北极地区的河流，这支持了以下结论，即排放泥炭丰富地区的较小河流系统的代表性不足可能导致低估全球陆地-海洋DOC输出。影响GB DOC出口空间分布的主要人为因素似乎是高地针叶种植园林，据估计，这使总DOC出口增加了0.168 Tg C年-1。这相当于目前英国森林净二氧化碳吸收率的15%。随着英国和许多其他国家寻求扩大种植园林覆盖率以减缓气候变化，这种“生态系统中的泄漏”应纳入未来对森林种植战略的CO2封存潜力的评估。
The dissolved organic carbon (DOC) export from land to ocean via rivers is a significant term in the global C cycle, and has been modified in many areas by human activity. DOC exports from large global rivers are fairly well quantified, but those from smaller river systems, including those draining oceanic regions, are generally under-represented in global syntheses. Given that these regions typically have high runoff and high peat cover, they may exert a disproportionate influence on the global land–ocean DOC export. Here we describe a comprehensive new assessment of the annual riverine DOC export to estuaries across the island of Great Britain (GB), which spans the latitude range 50–60° N with strong spatial gradients of topography, soils, rainfall, land use and population density. DOC yields (export per unit area) were positively related to and best predicted by rainfall, peat extent and forest cover, but relatively insensitive to population density or agricultural development. Based on an empirical relationship with land use and rainfall we estimate that the DOC export from the GB land area to the freshwater-seawater interface was 1.15 Tg C year−1in 2017. The average yield for GB rivers is 5.04 g C m−2year−1, higher than most of the world’s major rivers, including those of the humid tropics and Arctic, supporting the conclusion that under-representation of smaller river systems draining peat-rich areas could lead to under-estimation of the global land–ocean DOC export. The main anthropogenic factor influencing the spatial distribution of GB DOC exports appears to be upland conifer plantation forestry, which is estimated to have raised the overall DOC export by 0.168 Tg C year−1. This is equivalent to 15% of the estimated current rate of net CO2uptake by British forests. With the UK and many other countries seeking to expand plantation forest cover for climate change mitigation, this ‘leak in the ecosystem’ should be incorporated in future assessments of the CO2sequestration potential of forest planting strategies.
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DOI：
10.1016/b978-012323841-2/50014-2
发表时间：
2002
期刊：
--
影响因子：
--
作者：
G. Cauwet
通讯作者：
G. Cauwet
影响因子：
4.9
作者：
Berggren, Martin;Klaus, Marcus;Karlsson, Jan
通讯作者：
Karlsson, Jan
影响因子：
3.7
作者：
Berggren, Martin;del Giorgio, Paul A.
通讯作者：
del Giorgio, Paul A.
影响因子：
5.9
作者：
Christian, D. G.;Riche, A. B.;Yates, N. E.
通讯作者：
Yates, N. E.
影响因子：
18.3
作者：
Evans, Chris D.;Futter, Martyn N.;Kothawala, Dolly N.
通讯作者：
Kothawala, Dolly N.