Responses of an arctic landscape to Lateglacial and early Holocene climatic changes: the importance of moisture
Responses of an arctic landscape to Lateglacial and early Holocene climatic changes: the importance of moisture
复制标题
北极景观对晚冰期和全新世早期气候变化的响应：水分的重要性
DOI：
10.1016/s0277-3791(01)00116-0
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发表时间：
2002
影响因子：
4
通讯作者：
M. Kunz
中科院分区：
文献类型：
--
作者：
D. Mann;D. Peteet;R. Reanier;M. Kunz
北极生态系统的许多物理和生物过程是高纬度地区特有的，人们对它们对气候变化的敏感性知之甚少。阿拉斯加北方北极山麓的地表过程和植被变化的地层学记录揭示了苔原景观如何对13,000年至800014年期间的气候变化作出反应。泥炭沉积开始和灌木植被成为广泛的约。12，50014 CyrBP，可能是对更温暖和更潮湿气候的到来的反应。在11，00014 CyrBP之前，斜坡侵蚀的增加导致了山谷的快速冲积，杨树沿着辫状洪泛平原向北蔓延。在新仙女木（11，000 -10，00014 CyrBP）期间，湖泊水位下降，河流切割了他们的洪泛平原。杨属记录的中断表明其地理范围缩小，其他物种的花粉记录表明在此期间气候凉爽干燥。基泥炭可追溯到YD是罕见的，这表明沼泽化的速度放缓。10，00014 CyrBP之后，湖泊水位上升，河流再次迅速加积，发生了强烈的土壤侵蚀，杨树再次入侵该地区。潮湿的酸性苔原植被是广泛的850014 CyrBP沿着与潮湿，有机质丰富的土壤。气候变化的这些大规模影响大多涉及湿度的变化。虽然低温是北极气候最显著的特征，但有效湿度的变化可能是气候变化对北极地区产生许多影响的直接原因。
Many of the physical and biological processes that characterize arctic ecosystems are unique to high latitudes, and their sensitivities to climate change are poorly understood. Stratigraphic records of land–surface processes and vegetation change in the Arctic Foothills of northern Alaska reveal how tundra landscapes responded to climatic changes between 13,000 and 800014CyrBP. Peat deposition began and shrub vegetation became widespread ca. 12,50014CyrBP, probably in response to the advent of warmer and wetter climate. Increased slope erosion caused rapid alluviation in valleys, and Populus trees spread northward along braided floodplains before 11,00014CyrBP. Lake levels fell and streams incised their floodplains during the Younger Dryas (YD) (11,000–10,00014CyrBP). A hiatus in records of Populus suggest that its geographic range contracted, and pollen records of other species suggest a cooler and drier climate during this interval. Basal peats dating to the YD are rare, suggesting that rates of paludification slowed. Immediately after 10,00014CyrBP, lake levels rose, streams aggraded rapidly again, intense solifluction occurred, and Populus re-invaded the area. Moist acidic tundra vegetation was widespread by 850014CyrBP along with wet, organic-rich soils. Most of these landscape-scale effects of climatic change involved changes in moisture. Although low temperature is the most conspicuous feature of arctic climate, shifts in effective moisture may be the proximate cause for many of the impacts that climate change has in arctic regions.