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Re: Volcanoes (comments on pterosaur extinction)



At 04:19 PM 08/02/01 +0000, Ken Kinman wrote:
In any case one would
hardly expect herbivorous dinosaurs to inhabit freshly erupted lava fields
until a reasoable vegetation cover had evolved, again a matter of centuries,
even in a tropical climate.

Ronald I. Orenstein replied:

Is this true? In Hawaii it certainly does not necessarily take that long for lava flows to re-vegetate. Under the right conditions I think it is more likely to be decades than centuries (you can see this on the rainier parts of the big Island); ferns can establish themselves fairly quickly.


not necessarily that long. Ferns are opportunists and will quickly establish themselves in disturned environments (e.g. the fern-spore spike at both the KTB and TJB: immediately after the extinction, ferns, which had previously been a minor component of floras, dominated to the virtual exclusion of everything else.Mt St Helens is a recent example of *very* rapid estabishment of flora (initially ferns).
--
Emma C. Rainforth
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