[Taxacom] Long-distance oceanic dispersal (rafting) of Nothofagus species

[Kenneth Kinman]

Hi all,
      The recent thread got me thinking about a debate that some of us were having on taxacom almost 12 years ago.  Namely whether long-distance oceanic dispersal (by rafting) was a significant factor in the geographic distribution of some species of Nothofagus (sensu lato).
       My hypothesis was that large rafts of dislodged Nothofagus trees (due to tsunami or other massive flooding event) could have held some of their fruit above the ocean surface and rafted from Tasmania to New Zealand, where one or more  new species could evolve (due to founder effect).  This would be a relatively short rafting event compared to the much longer driftwood oceanic rafting that happened from South America to Tasmania: Barber, 1959, in the journal Nature; "Transport of Driftwood from South America to Tasmania". Is there other evidence that such dispersal of Nothofagus could have happened? Could certain insects, mosses, or other organisms have hitched a ride on such a Nothofagus raft?
                                   --------------Ken Kinman
http://mailman.nhm.ku.edu/pipermail/taxacom/2006-December/108385.html