Climate change and human impact at Sacrower See (NE Germany) during the past 13,000 years: a geochemical record
Climate change and human impact at Sacrower See (NE Germany) during the past 13,000 years: a geochemical record
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Sacrower See（德国东北部）过去 13,000 年来的气候变化和人类影响：地球化学记录
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
B. Zolitschka
中科院分区：
文献类型：
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作者：
D. Enters;D. Enters;E. Kirilova;A. Lotter;A. Lücke;Jörn Parplies;S. Jahns;G. Kuhn;B. Zolitschka
德国东北部的湖泊沉积物很少被用来作为档案，以解决气候变化和人类活动对该地区湖泊生态系统和景观演变的影响。萨克罗湖是位于勃兰登堡的一个硬水湖，提供了覆盖过去13，000年的独特沉积物记录，用于重建气候和人为对湖泊沉积的影响。时间控制是由12 AMS 14 C日期的陆生植物遗骸，Laacher看到火山灰，并开始纹形成在公元1870年（80卡尔。BP）。地球化学分析（包括主要元素的X射线荧光测井、CNS分析以及δ 13 Corg和δ 15 N测量）和花粉分析可以检测沉积物记录中详细的环境变化。在新仙女木寒冷期，土壤侵蚀增加，低层大气氧气消耗增加了湖水的营养供应，导致富营养化条件。全新世初期，C/N比值、全硫、有机质δ 13 C以及K、Si、Ti等元素变化较大，反映了湖泊流域对气候变暖的响应。重新造林减少了碎屑颗粒和陆地有机物的流入。人类影响的第一个相当弱的证据只记录在5,500卡路里的花粉记录中。BP.然而，直到3,200卡。BP沉积学和地球化学参数表明环境条件相对稳定。在3,200、2,800和900卡路里左右的强烈人类撞击期间。Ti和K的BP峰值分别代表了青铜时代、铁器时代和中世纪时期由于森林砍伐而导致的土壤侵蚀增加的阶段。一般而言，在这些扰动期间，大多数变量的变化较大，表明环境条件不太稳定。在全新世期间，生物硅积累率的稳步上升反映了Sacrower See的生产力不断提高，直到硅藻在上个世纪被其他藻类所淘汰。应用的多代理方法促进了对沉积物记录的解释，以揭示环境变化的一致画面，包括控制湖泊个体发育的环境因素和人类影响的影响。
Lacustrine sediments in north-eastern Germany have rarely been used as archives to address the effects of climate change and human impact on both lake ecosystem and landscape evolution for this region. Sacrower See, a hardwater lake located in Brandenburg, provides a unique sediment record covering the past 13,000 years which was used to reconstruct climatic and anthropogenic forcing on lacustrine sedimentation. Time control is provided by 12 AMS 14C dates of terrestrial plant remains, the Laacher See Tephra, and the onset of varve formation in AD 1870 (80 cal. BP). Geochemical (including XRF logging of major elements, CNS analyses as well as δ13Corg and δ15N measurements) and pollen analyses allowed detecting detailed environmental changes in the sediment record. During the Younger Dryas cold phase increased soil erosion and hypolimnetic oxygen depletion enhanced the nutrient supply to the lake water causing eutrophic conditions. The beginning of the Holocene is characterized by large changes in C/N ratios, total sulphur, δ13C of bulk organic matter as well as in K, Si, and Ti, reflecting the response of the lake’s catchment to climatic warming. Reforestation reduced the influx of detrital particles and terrestrial organic matter. The first, rather weak evidence of human impact is documented only in the pollen record at 5,500 cal. BP. However, until 3,200 cal. BP sedimentological and geochemical parameters indicate relatively stable environmental conditions. During periods of intense human impact at around 3,200, 2,800, and 900 cal. BP peaks in Ti and K represent phases of increased soil erosion due to forest clearing during the Bronze Age, Iron Age, and Medieval Times, respectively. In general, greater variation is observed in most variables during these perturbations, indicating less stable environmental conditions. The steady rise of biogenic silica accumulation rates during the Holocene reflects an increasing productivity of Sacrower See until diatoms were outcompeted by other algae during the last centuries. The applied multi-proxy approach fosters the interpretation of the sediment record to reveal a consistent picture of environmental change including environmental factors controlling lake ontogeny and the effects of human impact.