| The most popular theory is that the Amazonian forest was greatly reduced in size because of cool, dry conditions which favored the growth of savanna and grasslands. However, the Amazonian region wasn't necessarily arid simply because conditions in other parts of the continent were very dry. |
| Pollen samples have shown that it's possible the Amazon Basin may even have had a cool, moist climate at that time. Evidence of many grassland and savanna plants have been found in the Amazonian region, but there was also a high density of plants that need more water. It's possible that the forest wasn't substantially smaller than the present forest, and the grassland only moved into marginal areas around the drier south-east edge of the forest. |
tropical regions through time -- page 2 of 3
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[tropical forests] [water] [climate] [pollen]
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