In the core Amazon Basin, which was moist throughout the glacial period, allowing for more or less continuous forest, less genetic diversity is found among populations, Dick said. "There's less differentiation across the whole Amazon Basin than there is among sites in lower Central America."
The study is the first to make such comparisons of genetic diversity patterns in Central and South America. "We think similar patterns will be found in other widespread species," Dick said.
Learning how Symphonia responded to past climate conditions may be helpful for predicting how forests will react to future environmental change, Dick said.
"Under scenarios of increased warmth and drying, we can see that populations are likely to be constricted, particularly in Central America, but also that they're likely to persist, because Symphonia has persisted throughout Central America and the Amazon basin. That tells us that some things can endure in spite of a lot of forest change. However, past climate changes were not combined with deforestation, as is the case today. That combination of factors could be detrimental to many species---especially those with narrow ranges---in the next century."
|Contact: Nancy Ross-Flanigan|
University of Michigan