Holocene climate and environmental change in north-eastern Kamchatka (Russian Far East), inferred from a multi-proxy study of lake sediments
Holocene climate and environmental change in north-eastern Kamchatka (Russian Far East), inferred from a multi-proxy study of lake sediments
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DOI：
10.1016/j.gloplacha.2015.02.013
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发表时间：
2015-11-01
影响因子：
3.9
通讯作者：
Hammarlund, Dan
中科院分区：
文献类型：
--
作者：
Andren, Elinor;Klimaschewski, Andrea;Hammarlund, Dan
本文对堪察加半岛东北部一个小湖泊的沉积物记录进行了多代理研究，以了解全新世的气候和环境变化。分析了花粉、硅藻、手摇虫和选定的地球化学参数，并用放射性碳定年了沉积物记录。研究揭示了全新世陆生植被的变化，以及湖泊生态系统对集水区成熟度和气候变化、火山爆发等多重压力源的响应。气候变化是导致该湖泊环境变化的主要驱动力，尽管反复发生的温度沉积事件也有贡献。沉积物记录的年代约为1万cal - ybp，前400年气候寒冷，湖泊冬季覆盖广泛，初级生产力相对较低。集水区土壤贫瘠，湖周围植被以灌木桤木和桦树为主。约9600 ~ 8900 cal - ybp气候寒冷湿润，强烈的季节性风胁迫导致冰盖减少，初级生产增加。约8900 cal - ybp后，湖泊周围的森林密度增加，在普遍干燥的气候下，径流减少，导致湖泊初级生产减少，直到约7000 cal - ybp。这种普遍干燥的气候被短暂的气候扰动打断，可能归因于8.2 ka事件，表明多风条件增加，积雪厚，冰盖减少，湖泊初级产量略有增加。硅藻记录显示，在约6300-5800 cal - ybp之间存在最大的热分层，并与地球化学指标一起表明，气候干燥且略暖，导致湖泊高产。流域植被最显著的变化发生在约4200 calyr BP，表现为西伯利亚矮松（Pinus pumila）的显著增加，表明气候向较冷的气候转变，积雪更厚、更持久。这种植被变化伴随着硅藻和摇尾藻地层的明显变化，这也表明气候更冷，冰盖更广泛。(C) 2015年作者。Elsevier B.V.出版
A sediment record from a small lake in the north-eastern part of the Kamchatka Peninsula has been investigated in a multi-proxy study to gain knowledge of Holocene climatic and environmental change. Pollen, diatoms, chironomids and selected geochemical parameters were analysed and the sediment record was dated with radiocarbon. The study shows Holocene changes in the terrestrial vegetation as well as responses of the lake ecosystern to catchment maturity and multiple stressors, such as climate change and volcanic eruptions. Climate change is the major driving force resulting in the recorded environmental changes in the lake, although recurrent tephra deposition events also contributed. The sediment record has an age at the base of about 10,000 cal yrs BP, and during the first 400 years the climate was cold and the lake exhibited extensive ice-cover during winter and relatively low primary production. Soils in the catchment were poor with shrub alder and birches dominating the vegetation surrounding the lake. At about 9600-8900 cal yrs BP the climate was cold and moist, and strong seasonal wind stress resulted in reduced ice-cover and increased primary production. After ca. 8900 cal yrs BP the forest density increased around the lake, runoff decreased in a generally drier climate resulting in decreased primary production in the lake until ca. 7000 cal yrs BP. This generally dry climate was interrupted by a brief climatic perturbation, possibly attributed to the 8.2 ka event, indicating increasingly windy conditions with thick snow cover, reduced ice-cover and slightly elevated primary production in the lake. The diatom record shows maximum thermal stratification at ca. 6300-5800 cal yrs BP and indicates together with the geochemical proxies a dry and slightly warmer climate resulting in a high productive lake. The most remarkably change in the catchment vegetation occurred at ca. 4200 cal yrs BP in the form of a conspicuous increase in Siberian dwarf pine (Pinus pumila), indicating a shift to a cooler climate with a thicker and more long-lasting snow cover. This vegetational change was accompanied by marked shifts in the diatom and chironomid stratigraphies, which are also indicative of colder climate and more extensive ice-cover. (C) 2015 The Authors. Published by Elsevier B.V.