The Holocene environmental history of a small coastal lake on the north-eastern Kamchatka Peninsula
The Holocene environmental history of a small coastal lake on the north-eastern Kamchatka Peninsula
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堪察加半岛东北部沿海小湖的全新世环境历史
DOI：
10.1016/j.gloplacha.2015.06.010
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发表时间：
2015
影响因子：
3.9
通讯作者：
Solovieva N
中科院分区：
文献类型：
--
作者：
Solovieva N
对来自堪察加半岛东北海岸救生圈湖的放射性碳和火山灰定年沉积物岩心进行了花粉、孢子、硅藻、摇蚊和火山灰，以揭示区域环境历史。救生圈湖6500年的环境历史与植被发育和气候动态的广泛区域模式相关，其中硅藻和摇蚊均表现出近-同步变化。6300和3900 cal yr BP时，湖泊生态系统自然富集，硅藻以几种千金藤属（Stephanocussp.）这种自然的富营养化状态可能是由于集水区富含碱的地质、集水区几次火灾的施肥效应、火山灰层的二氧化硅输入以及海鸟的氮输入等因素综合作用的结果。BP约3850卡尔年的大量火山灰存款可能阻止了沉积磷进入湖水，从而降低了湖泊的营养状态，并促进了硅藻组成向底栖脆枝藻科复合体的转变。硅藻和摇蚊都表现出同时的组成变化，这也反映在统计上的显着变化率的变化后300-400年的到来pumilin湖集水区。硅藻总浓度和大型重种Aulacoseira subarctica丰度的迅速增加可能是由于北太平洋大气环流形势的变化，特别是阿留申低压的向西移，导致湖泊春季转换时间和强度变化的响应。在Lifebouy湖的subarcticabundance发生在相反的夏季温度推断：早期的高峰（3500-2900卡年BP）与温暖的夏季和后期的高峰（300卡年BP目前）发生在寒冷的夏季期间。这意味着A.对夏季气温变化无直接响应。相反，它似乎在冬季降水增加、冰层变厚和晚春更替期间茁壮成长，即，火山灰沉积对湖泊生态系统的影响最明显的是在908 cm（约. 3800 cal yr BP），火山灰存款可能导致了底栖物种从千金藤占主导地位的浮游生物组合的转变。火山碎屑沉积物也可能有助于从约6300卡年BP的富营养化浮游生物的发展。在过去的300年里，几个火山灰沉积物是否影响了硅藻和摇蚊的变化尚不确定。
A radiocarbon and tephra-dated sediment core from Lifebuoy Lake, located on the north-east coast of Kamchatka Peninsula, was analysed for pollen, spores, diatoms, chironomids and tephra in order to uncover regional environmental history.The 6500-year environmental history of Lifebuoy Lake correlates with the broad regional patterns of vegetation development and climate dynamics with both diatoms and chironomids showing near-synchronous changes.Between ca. 6300 and 3900 cal yr BP, the lake ecosystem was naturally enriched, with severalStephanodiscusspecies dominating the diatom plankton. This natural eutrophication state is likely to be due to a combination of the base-rich catchment geology, the fertilisation effect of several fires in the catchment, silica input from tephra layers and, possibly, nitrogen input from seabirds. The substantial tephra deposit at about 3850 cal yr BP might have stopped sedimentary phosphorus from entering the lake water thus decreasing the trophic state of the lake and facilitating the shift in diatom composition to a benthic Fragiliariaceae complex.Both diatoms and chironomids showed simultaneous compositional changes, which are also reflected by statistically significant changes in their rates of change 300–400 years after the arrival ofPinus pumilain the lake catchment. The rapid increase in both total diatom concentration and the percentage abundance of the large heavy species,Aulacoseira subarcticamight be a response to the change in timing and intensity of lake spring turn-over due to the changes in the patterns of North Pacific atmospheric circulation, most notably westward shift of the Aleutian Low.The two highest peaks inA. subarcticaabundance at Lifebouy Lake occurred during opposite summer temperature inferences: the earlier peak (3500–2900 cal yr BP) coincided with warm summers and the latter peak (300 cal yr BP–present) occurred during the cold summer period. These imply thatA. subarcticashows no direct response to the changes of summer air temperature. Instead, it appears to thrive during the periods of increased winter precipitation, thicker ice and late spring turn-over periods, i.e., shows indirect response to climate.The clearest effect of tephra deposition on the lake ecosystem is above 908 cm (ca. 3800 cal yr BP) where the tephra deposit might have caused the shift fromStephanodiscus-dominated planktonic assemblages to the Fragilariaceae complex of benthic species. Tephra deposits might have also contributed towards the development of eutrophic plankton from about 6300 cal yr BP. It is not certain if several tephra deposits influenced diatom and chironomid changes during the last 300 years.
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DOI：
--
发表时间：
1993
期刊：
Radiocarbon: An International Journal of Cosmogenic Isotope Research
影响因子：
--
作者：
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2006
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DOI：
--
发表时间：
1993
期刊：
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作者：
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DOI：
--
发表时间：
1994
期刊：
影响因子：
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作者：
M. Edwards;E. Barker
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E. Barker
影响因子：
56.9
作者：
Goebel, T;Waters, MR;Dikova, M
通讯作者：
Dikova, M