Quaternary forest associations in lowland tropical West Africa
Quaternary forest associations in lowland tropical West Africa
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DOI：
10.1016/j.quascirev.2013.10.027
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发表时间：
2014-01
影响因子：
4
通讯作者：
Charlotte Miller;W. Gosling
中科院分区：
文献类型：
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作者：
Charlotte Miller;W. Gosling
陆地化石花粉记录经常被用来揭示植被对区域和全球气候变化的响应。在这里，我们提出了一个化石花粉记录从沉积物芯提取的湖Bosumtwi（西非）。该记录涵盖了过去的52万年（ka），是迄今为止出版的非洲最长的陆地花粉记录。化石花粉组合揭示了植被的动态变化，可以广泛地表征为萨凡纳和森林之间的转变的指示。萨凡纳地层主要由禾本科花粉（>55%）组成，通常与莎草科、藜科-苋科和石竹科有关。森林形成的孢粉学更多样性比萨凡纳草原，与关键类群发生在多个森林地带是桑科，朴属，乌帕卡，MacarangaandTrema.The化石花粉数据表明，在过去的c.520 ka的植被的低地热带西非主要是萨凡纳，但6个时期的森林扩张是显而易见的，最有可能对应于全球间冰期。森林组合组成的比较表明，全新世（11-0 ka）的森林发生在最潮湿的气候，而海洋同位素阶段7时发生的森林可能发生在最干燥的气候。
Terrestrial fossil pollen records are frequently used to reveal the response of vegetation to changes in both regional and global climate. Here we present a fossil pollen record from sediment cores extracted from Lake Bosumtwi (West Africa). This record covers the lastc.520 thousand years (ka) and represents the longest terrestrial pollen record from Africa published to date. The fossil pollen assemblages reveal dynamic vegetation change which can be broadly characterized as indicative of shifts between savannah and forest. Savannah formations are heavily dominated by grass (Poaceae) pollen (>55%) typically associated with Cyperaceae, Chenopodiaceae–Amaranthaceae and Caryophyllaceae. Forest formations are palynologically more diverse than the savannah, with the key taxa occurring in multiple forest zones being Moraceae,Celtis,Uapaca,MacarangaandTrema.The fossil pollen data indicate that over the lastc.520 ka the vegetation of lowland tropical West Africa has mainly been savannah; however six periods of forest expansion are evident which most likely correspond to global interglacial periods. A comparison of the forest assemblage composition within each interglacial suggests that the Holocene (11–0 ka) forest occurred under the wettest climate, while the forest which occurred at the time of Marine Isotope Stage 7 probably occurred under the driest climate.