Annual layer counting using pollen grains of the Grigoriev ice core from the Tien Shan Mountains, central Asia
Annual layer counting using pollen grains of the Grigoriev ice core from the Tien Shan Mountains, central Asia
复制标题
DOI：
10.1080/15230430.2019.1638202
复制
发表时间：
2019-01
期刊：
影响因子：
--
通讯作者：
N. Takeuchi;S. Sera;K. Fujita;V. Aizen;J. Kubota
中科院分区：
文献类型：
--
作者：
N. Takeuchi;S. Sera;K. Fujita;V. Aizen;J. Kubota
花粉粒普遍存在于冰芯中，特别是中低纬度山地冰川的冰芯中。由于花的花粉释放具有季节性，并且在不同的植物物种之间有所不同，因此冰芯中的花粉浓度有助于区分年层或季节层，并推断冰川附近过去的植被。我们分析了在吉尔吉斯斯坦天山Grigoriev冰冠（4563 m.a.s.l.）顶部钻取的87 m深冰芯中的主要花粉粒。显微镜观察显示，冰芯中主要含有5个花粉类群。它们的丰度随岩心的深度而波动，表明它们在冰盖上的季节性沉积，而稳定同位素的季节性由于融化和再冻结的特征而不是特别清楚。根据花粉剖面，确定了63.6 m深度至公元1780年的年层数；在更深的地方，由于冰川的冰层变薄，它们无法被区分。近220年来，该地区的花粉组合逐渐发生变化，其中较深部分的变化尤为明显，表明该地区在全新世期间发生了剧烈的植被变化。
ABSTRACT Pollen grains are commonly found in ice cores, particularly those from mountain glaciers at low to middle latitudes. Because the release of pollen from flowers has a seasonality and varies among the plant species, pollen concentrations in ice cores are useful for distinguishing annual or seasonal layers and inferring past vegetation near glaciers. We analyzed major pollen grains in an 87-m-deep ice core drilled at the top of the Grigoriev Ice Cap (4563 m.a.s.l.) in the Tien Shan Mountains, Kyrgyz Republic. Microscopy showed that mainly five pollen taxa were contained in the ice core. Their abundance fluctuated with the depth of the core, indicating their seasonal deposition on the ice cap, while the seasonality of the stable isotopes was not particularly clear because of melting and refreezing signatures. Based on the pollen profiles, annual layers were determined back in time to 1780 AD at a depth of 63.6 m; at greater depth, they could not be distinguished due to ice layer thinning in the glacier. The pollen assemblages have gradually changed during the last 220 years and were particularly distinctive in the deeper part, suggesting the drastic change of vegetation in this region during the Holocene.