[Taxacom] Shorter trans-oceanic dispersal of Nothofagus
kennethkinman at webtv.net
Tue Jul 27 21:03:29 CDT 2010
I can totally understand the reluctance to accept a very long
trans-oceanic dispersal of Nothofagus from Chile to New Zealand (or even
vice versa). It seems unnecessary given most present data, but new data
and reinterpretations of old data may eventually change things. Time
In the meantime, I wonder if this reluctance also applies to
shorter distance trans-oceanic dispersal of Nothofagus, particularly
between Australia and New Zealand (either way). I wouldn't be surprised
if panbiogeographers would poo-poo even that idea, but what about you
non-panbiogeographers? Is the trans-oceanic dispersal of whole
Nothofagus trees (fruit plus ectomycorrhiza) that difficult to swallow?
Sure, you put Nothofagus seeds in salt water and they don't sprout, but
what about seeds transported within the fruit (husk). How vulnerable
are they to the salt water, especially if the branches they are hanging
from are floating well above the ocean waves? And if such trees were
washed out to sea by a massive flood, the fruits would be saturated by
fresh water during the initial part of the journey (which would help to
dilute any salt water trying to penetrate the fruit further out to sea.
The journey between Australia and New Zealand (or vice versa) is much
shorter, and therefore seems far more immune to the objections voiced
against a South America to New Zealand dispersal.
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