Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil.
Instituto de Geociências, Universidade de São Paulo, São Paulo, Brazil.
Sci Rep. 2019 Nov 14;9(1):16879. doi: 10.1038/s41598-019-53465-y.
The Amazonian landscape evolution is the result of the combined effect of Andean tectonism, climate and the Earth's interior dynamics. To reconstruct the landscape evolution and its influence on paleoenvironmental variations within Amazonia since the Oligocene, we conducted numerical experiments that incorporate different surface and geodynamic processes, reproducing many paleogeographic features as inferred from the sedimentary record. We show that the evolution of the drainage pattern gradually reduced the area of sedimentation derived from the Guiana and Brazilian shields while expanded the Andean derived deposits during the Miocene, affecting the nutrient availability. First order biotic habitats were inferred from these paleogeographical reconstructions, showing an eastward expansion of várzea and terra firme forests and consequent retraction of igapó forests, with a millennial-scale reconfiguration of a mosaic of habitats in the lowlands. We conclude that this dynamism probably guided the observed patterns of speciation in the most biodiverse biome on Earth.
亚马孙地区的地貌演化是安第斯构造运动、气候和地球内部动力学共同作用的结果。为了重建上新世以来亚马孙地区的地貌演化及其对古环境变化的影响，我们进行了数值实验，这些实验结合了不同的地表和地球动力学过程，再现了许多从沉积记录推断出的古地理特征。研究结果表明，水系的演化逐渐减少了源自圭亚那和巴西地盾的沉积物面积，而在中新世时增加了源自安第斯山脉的沉积物，从而影响了养分的可利用性。从这些古地理重建中推断出了一级生物栖息地，显示出瓦尔德泽和特费尔雷森林向东扩展，而伊加波森林退缩，低地的生境镶嵌也以千年为尺度进行重新配置。研究结论认为，这种动态变化可能指导了地球上生物多样性最丰富的生物群落中观察到的物种形成模式。
