Postglacial vegetation dynamics of western Tierra del Fuego †
Postglacial vegetation dynamics of western Tierra del Fuego †
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DOI：
10.1177/0959683612444144
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发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
Sonia L. Fontana;K. Bennett
中科院分区：
文献类型：
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作者：
Sonia L. Fontana;K. Bennett
南美洲大陆的南部边缘提供了一个难得的机会，研究在南半球潮湿、凉爽的温带气候中，树木覆盖稀疏的高沼地植被的发展。我们提供了过去17，000年来植被变化的记录，来自智利最南端的一个湖泊（Isla Santa Inés，马加拉内斯地区，53° 38.97 S; 72° 25.24 W），人类对植被的影响可以忽略不计。火地岛西部的群岛在晚冰期的大部分时间里都没有树木，植被主要是石松（Lycopodium magellanicum）、Gunnera magellanica和石南（Heath）。Nothofagus可能在麦哲伦冰川东部边缘的最后一次盛冰期中幸存下来，并从那里向西南传播，并在大约10，500 cal. yr BP的地区建立。南极假法甲树可能是西部岛屿最早的殖民树，不久之后是北美假法甲树。在9000 cal. yr BP高沼地社区扩大在牺牲Nothofagus林地。同时，Nothofagus物种转移到万年青Nothofagus betuloides和麦哲伦雨林建立在该地区的优势。快速和剧烈的植被变化发生在5200 cal. yr BP，山伯尼MB 2喷发后，包括扩大和建立Pilgerodendron uviferum和混合假山毛榉-Drimys林地的发展。分散的人口Nothofagus，因为他们今天发生在最西端的火地岛可能是一个很好的模拟Nothofagus人口在晚冰期在东部网站。
The southern fringes of the South American landmass provide a rare opportunity to examine the development of moorland vegetation with sparse tree cover in a wet, cool temperate climate of the Southern Hemisphere. We present a record of changes in vegetation over the past 17,000 years, from a lake in extreme southern Chile (Isla Santa Inés, Magallanes region, 53°38.97S; 72°25.24W), where human influence on vegetation is negligible. The western archipelago of Tierra del Fuego remained treeless for most of the Lateglacial period; Lycopodium magellanicum, Gunnera magellanica and heath species dominated the vegetation. Nothofagus may have survived the last glacial maximum at the eastern edge of the Magellan glaciers from where it spread southwestwards and established in the region at around 10,500 cal. yr BP. Nothofagus antarctica was likely the earlier colonizing tree in the western islands, followed shortly after by Nothofagus betuloides. At 9000 cal. yr BP moorland communities expanded at the expense of Nothofagus woodland. Simultaneously, Nothofagus species shifted to dominance of the evergreen Nothofagus betuloides and the Magellanic rain forest established in the region. Rapid and drastic vegetation changes occurred at 5200 cal. yr BP, after the Mt Burney MB2 eruption, including the expansion and establishment of Pilgerodendron uviferum and the development of mixed Nothofagus-Pilgerodendron-Drimys woodland. Scattered populations of Nothofagus, as they occur today in westernmost Tierra del Fuego may be a good analogue for Nothofagus populations during the Lateglacial in eastern sites.