Biology Reference
In-Depth Information
Figure 2.45
Ecological subdivisions (fl oristic regions and vegetation types) of South America.
From Young and others 2007 (see also references cited therein). Used with permission from
Oxford University Press, Oxford.
because they allow for rapid response of the vegetation to environmental
change. Also, they fi gure prominently in models proposed to explain the
high levels of biodiversity based on periodic fragmentation and reuniting of
habitats and the biota due to changes in climate (chap. 9, Refugia).
There are three key geologic questions relating to the biotic history of
northern and central South America: (a) What was the early environment
like in the Amazon Basin during the Cretaceous and Tertiary? (b) When did
