Heterogeneity in global vegetation and terrestrial climate change during the late Eocene to early Oligocene transition.
Heterogeneity in global vegetation and terrestrial climate change during the late Eocene to early Oligocene transition.
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DOI：
10.1038/srep43386
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发表时间：
2017-02-24
影响因子：
4.6
通讯作者：
Salzmann U
中科院分区：
文献类型：
--
作者：
Pound MJ;Salzmann U
在始新世-渐新世过渡期（EOT），约33.9 - 33.5 Ma，全球快速冷却被广泛认为标志着现代冰室世界的开始。大气中pCO2的大幅度快速下降被认为是海洋领域和南极洲冰川作用背后的驱动力。然而，全球陆地对这种冷却的反应是不确定的。在这里，我们提出了第一个全球植被和陆地温度重建的EOT。使用广泛的孢粉数据集，已被统计分组为古生物群落，我们表明陆地气候变化的过渡性，在EOT在两个半球的植被变化的时空异质性。重建的地球温度显示，许多地区的冷却，早在EOT开始，并持续到早渐新世。我们的结论是，全球植被变化的异质模式已被控制的多种强迫，如构造，海平面下降和长期下降的温室气体浓度在始新世晚期到渐新世早期的组合，并不代表一个单一的响应，在EOT大气pCO2的快速下降。
Rapid global cooling at the Eocene – Oligocene Transition (EOT), ~33.9–33.5 Ma, is widely considered to mark the onset of the modern icehouse world. A large and rapid drop in atmospheric pCO2 has been proposed as the driving force behind extinctions in the marine realm and glaciation on Antarctica. However, the global terrestrial response to this cooling is uncertain. Here we present the first global vegetation and terrestrial temperature reconstructions for the EOT. Using an extensive palynological dataset, that has been statistically grouped into palaeo-biomes, we show a more transitional nature of terrestrial climate change by indicating a spatial and temporal heterogeneity of vegetation change at the EOT in both hemispheres. The reconstructed terrestrial temperatures show for many regions a cooling that started well before the EOT and continued into the Early Oligocene. We conclude that the heterogeneous pattern of global vegetation change has been controlled by a combination of multiple forcings, such as tectonics, sea-level fall and long-term decline in greenhouse gas concentrations during the late Eocene to early Oligocene, and does not represent a single response to a rapid decline in atmospheric pCO2 at the EOT.