High‐resolution pollen analysis of tundra polygons from the North Slope of Alaska
High‐resolution pollen analysis of tundra polygons from the North Slope of Alaska
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阿拉斯加北坡苔原多边形的高分辨率花粉分析
DOI：
10.1029/98jd01462
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发表时间：
1998
影响因子：
--
通讯作者：
K. Peterson
中科院分区：
文献类型：
--
作者：
W. Eisner;K. Peterson
现代和化石花粉分析建立了当地植被演替和景观演变沿着米德河附近的Atqasuk，阿拉斯加。分析了三个数据集：（1）暴露的河流海崖面上的142 cm长的泥炭存款，（2）近地表沉积物中的13 cm短泥炭整料，以及（3）沿沿着代表低中心、过渡和高中心多边形地貌梯度的断面采集的地表样品的现代数据集。花粉-微体化石组合在这一梯度上沿着变化显著。对短花粉剖面的详细分析显示了过去250年来植被的演替变化。长剖面图记录了过去9400年的植被，表明该遗址最初被浅水湖泊覆盖。风沙活动对沉积物的沉积有很大的影响，但一个时期的快速泥炭生长从8500至5000 14 C年B. P.是一致的植被覆盖的混合草-灌木苔原。在这一时期之后，泥炭生长放缓，灌木植被被丛生的莎草植被所取代。
Modern and fossil pollen analyses have established the local vegetation succession and landscape evolution along the Meade River near Atqasuk, Alaska. Three data sets were analyzed: (1) a 142-cm-long peat deposit on the exposed river bluff face, (2) a short, 13-cm peat monolith from the near-surface sediment, and (3) a modern data set of surface samples collected along a transect representative of a geomorphic gradient of low-center, transitional, and high-center polygons. Pollen-microfossil assemblages changed significantly along this gradient. Detailed analysis of the short pollen profile shows successional vegetation changes over the last 250 years. The long profile, a 9400-year record of past vegetation, indicates that initially, the site was covered by shallow lakes. Eolian activity had a substantial effect on sediment deposition, but a period of rapid peat growth from 8500 to 5000 14C year B.P. is coincident with increased vegetation cover of mixed grass-shrub tundra. Following this period, peat growth slowed, and shrub vegetation was replaced by tussock-forming sedge vegetation.