15,000 years of black carbon deposition – A post-glacial fire record from maar lake sediments (Germany)
15,000 years of black carbon deposition – A post-glacial fire record from maar lake sediments (Germany)
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DOI：
10.1016/j.quascirev.2014.12.014
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发表时间：
2015-02
影响因子：
4
通讯作者：
E. Lehndorff;M. Wolf;T. Litt;A. Brauer;W. Amelung
中科院分区：
文献类型：
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作者：
E. Lehndorff;M. Wolf;T. Litt;A. Brauer;W. Amelung
在整个全新世，火灾伴随着人类的发展，留下了黑碳（BC）作为不完全生物质燃烧的残留物。在这里，我们使用分子火灾标志物，苯多羧酸（BPCA），重建火灾历史的两个艾菲尔玛湖，德国。我们假设找到以下迹象：（i）与生态系统变化相关的BC变化，（ii）在农业开始时BC流入量的增加，直到现代，以及（iii）由于燃烧技术的进步，BC质量的变化，例如，农业开始和青铜时代开始时。为了计算进入玛珥湖的绝对BC流入量，我们将BC含量乘以沉积速率。在晚更新世的苔原状植被期间，BC的流入率升高（高达7.7 g BC m−2a−1），随后从博林（Bølling）间冰丘（>13.7 kilo years before present，ka BP）到大西洋早期森林开始发展，BC的流入率相对稳定，为2.5 g BC m−2a− 1。此后，随着该地区新石器文化土地利用的开始，BC流入量从7.5 ka BP增加到7-9 g BC m−2a−1。值得注意的是，BC的质量也发生了变化：较高的五至六次羧基化苯（B5 CA/B6 CA）的比例表明，在新石器时代第一次活动后约1000年，从6到4 ka BP（B5 CA/B6 CA从1.0增加到2.0）。从4ka BP（青铜时代）到现代，燃烧温度的升高（B5 CA/B6 CA比值从2.0下降到1.0）与冶金和工业化有关。在2.5 ~ 1 ka BP之间，BC的最大流入速率达到约15 g BC m−2a−1。随着燃烧效率的提高和野火的减少，在过去的几个世纪里，总的BC流入量下降，这表明化石燃料燃烧贡献的总BC输入到湖泊沉积物比以前的植被火灾。
Fires accompanied human development throughout the Holocene, leaving behind black carbon (BC) as residues from incomplete biomass burning. Here we used molecular fire markers, benzene polycarboxylic acids (BPCAs), to reconstruct fire history in two Eifel maar lakes, Germany. We hypothesized to find indications for (i) changes in BC related to ecosystem changes, (ii) an increase in BC influx at the onset of agriculture until modern times, and (iii) a change in BC quality due to technical progress in combustion, e.g., at the beginning of agriculture and at the onset of the Bronze Age. To calculate absolute BC influx into the maar lakes, we multiplied BC contents with sedimentation rates. The BC influx rates were elevated during tundra-like vegetation in the Late Pleistocene (up to 7.7 g BC m−2a−1), followed by relatively constant 2.5 g BC m−2a−1from the Bølling interstadial (>13.7 kilo years before present, ka BP) until the early Atlantic when forest began to develop. Thereafter, BC influx increased with the onset of land use of Neolithic cultures in the region from 7.5 ka BP to rates of 7–9 g BC m−2a−1. Noteworthy, also the quality of BC changed: higher ratios of five-to six-times carboxylated benzenes (B5CA/B6CA) pointed at colder, arable fires approximately 1000 years after first Neolithic activity from 6 to 4 ka BP (B5CA/B6CA increased from 1.0 to 2.0). From 4 ka BP (Bronze Age) to modern times increasing burning temperatures as indicated by dropping B5CA/B6CA ratios (from 2.0 to 1.0) were related to metallurgy and industrialization. Between 2.5 and 1 ka BP maximum BC influx rates were reached with ca 15 g BC m−2a−1. With increasing combustion efficiency and a reduction of wild fires during the last centuries, total BC influx decreased, suggesting that fossil fuel combustion contributed less to total BC input into the lake sediments than former vegetation fires.