Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes
Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes
复制标题
DOI：
10.1007/s10021-019-00368-8
复制
发表时间：
2019-12-01
期刊：
影响因子：
3.7
通讯作者：
Yang, H.
中科院分区：
文献类型：
--
作者：
Anderson, N. J.;Appleby, P. G.;Yang, H.
湖泊是北极景观的一个关键特征，也是区域有机碳(OC)预算的重要组成部分，但C埋藏率没有得到很好的估计。利用PB-210测年沉积物岩心和碳、有机质(烧失量)估算了格陵兰西南部16个湖泊的有机碳埋藏。利用铅-210通量法对沉积物聚焦的埋藏率进行了修正。所研究的湖泊跨越了一系列水化学物质(电导率范围25-3400亩S厘米(-1))、面积(4-100公顷)和最大深度(类似于10-50米)。经聚焦校正的区域平均有机碳累积速率在1950年前为2gCm(-2)y(-1)，在1950年后为3.6gCm(-2)y(-1)。1950年后OC AR的湖间变异性与湖内溶解有机碳浓度、电导率、海拔高度和峡湾所处的地理位置相关。在分析的时间段内，有12个湖泊表现出平均OC AR的增加，类似于1880-2000年；由于研究区直到最近还在降温，这种增加可能是由于其他全球变化过程，例如N或P的输入发生了变化。研究区有大约2万个湖泊，面积从相似的1公顷到130公里(2)不等，尽管超过83%的湖泊面积小于10 ha。将1950年后的平均OC AR(3.6gCm(-2)y(-1))外推到所有大于1000公顷的湖泊，并对大型湖泊(>；1000公顷)应用类似于2gCm(-2)y(-1)的较低速率，得出1950年后区域湖泊OC埋藏率类似于10.14×10(-9)gCy(-1)。考虑到这一地区土壤的低碳含量，湖泊代表着相当大的区域碳库。
Lakes are a key feature of arctic landscapes and can be an important component of regional organic carbon (OC) budgets, but C burial rates are not well estimated. Pb-210-dated sediment cores and carbon and organic matter (as loss-on-ignition) content were used to estimate OC burial for 16 lakes in SW Greenland. Burial rates were corrected for sediment focusing using the Pb-210 flux method. The study lakes span a range of water chemistries (conductivity range 25-3400 mu S cm(-1)), areas (< 4-100 ha) and maximum depths (similar to 10-50 m). The regional average focusing-corrected OC accumulation rate was similar to 2 g C m(-2) y(-1) prior to 1950 and 3.6 g C m(-2) y(-1) after 1950. Among-lake variability in post-1950 OC AR was correlated with in-lake dissolved organic carbon concentration, conductivity, altitude and location along the fjord. Twelve lakes showed an increase in mean OC AR over the analyzed time period, similar to 1880-2000; as the study area was cooling until recently, this increase is probably attributable to other global change processes, for example, altered inputs of N or P. There are similar to 20,000 lakes in the study area ranging from similar to 1 ha to more than 130 km(2), although over 83% of lakes are less than 10 ha. Extrapolating the mean post-1950 OC AR (3.6 g C m(-2) y(-1)) to all lakes larger than 1000 ha and applying a lower rate of similar to 2 g C m(-2) y(-1) to large lakes (> 1000 ha) suggests a regional annual lake OC burial rate of similar to 10.14 x 10(9) g C y(-1) post 1950. Given the low C content of soils in this area, lakes represent a substantial regional C store.