The influence of abrupt climate change on the ice-age vegetation of the Central American lowlands
The influence of abrupt climate change on the ice-age vegetation of the Central American lowlands
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DOI：
10.1111/j.1365-2699.2011.02618.x
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发表时间：
2012-03-01
影响因子：
3.9
通讯作者：
Guilderson, Tom
中科院分区：
文献类型：
--
作者：
Correa-Metrio, Alexander;Bush, Mark B.;Guilderson, Tom
目的研究北大西洋气候突变对中美洲低地植被历史的影响。我们使用来自尤卡坦半岛半岛中美洲湖泊的孢粉学证据，以评估在最后一个冰河时代，65和8万年之间的快速气候变化的影响。位置佩滕伊察湖，危地马拉北方的低地。方法在c. 170-年分辨率的花粉和木炭分析，以构建一个时间序列的环境变化。对花粉数据集进行了单变量和多变量统计分析，以检验北大西洋海因里希事件与中美洲低地植被变化之间是否存在关联。结果花粉分析表明，尤卡坦半岛植物群落的组成随北大西洋气候的快速变化而发生阶段性变化。松疏林是C. 60和47 ka。这些稀树草原让位给松树橡树（松栎）森林在后半期的最后一个冰河时代。显着的事件发生在海因里希事件的松树橡树组合的耐旱类群的更换。末次盛冰期（LGM）以中冰期为特征。主要结论贝登-伊察湖的花粉记录表明，与海因里希事件相关的植被变化比与末次盛冰期相关的植被变化更显著。每一次海因里希事件都产生了向旱生类群的特征性转变。虽然比海因里希事件冷，在尤卡坦半岛的末次盛冰期是相对潮湿的，和假定的草原化景观在最大冷却的末次冰期是不支持我们的数据。我们的研究结果表明，在冰川时期的植物多样化和遗传交换的替代方案，也表明，在热带大陆设置的植被并不像以前认为的那样稳定。
Aim To investigate the effects of abrupt climate change in the North Atlantic on the vegetation history of lowland Central America. We use palynological evidence from a Central American lake on the Yucatan Peninsula to evaluate the effects of rapid climate changes during the last ice age, between 65 and 8 ka. Location Lake Peten-Itza, lowlands of northern Guatemala. Methods Sediment core PI-6 was sampled at c. 170-year resolution for pollen and charcoal analysis in order to construct a temporal sequence of environmental change. Uni-and multivariate statistical analyses were performed on the pollen dataset to test whether there was an association between Heinrich events in the North Atlantic and vegetation changes in the Central American lowlands. Results Pollen analysis revealed that the composition of plant assemblages on the Yucatan Peninsula varied in phase with rapid changes in North Atlantic climate. Pine savannas were the main vegetation type between c. 60 and 47 ka. These savannas gave way to pine-oak (Pinus-Quercus) forests in the latter half of the last ice age. Marked episodes of replacement of the pine-oak assemblage by xeric-tolerant taxa occurred during Heinrich events. The Last Glacial Maximum (LGM) was characterized by mesic conditions. Main conclusions The pollen record from Lake Peten-Itzashowed that vegetation changes associated with Heinrich events were more significant than those associated with the LGM. Each Heinrich event produced a characteristic shift towards xeric taxa. Although colder than Heinrich events, the LGM on the Yucatan Peninsula was relatively moist, and the presumed savannization of the landscape during the maximum cooling of the last glacial was not supported by our data. Our findings suggest alternative scenarios for plant diversification and genetic interchange during glacial times, and also indicate that vegetation in tropical continental settings was not as stable as previously thought.