function of bark

[Carol Auer]

Hello

I teach a plant identification class and a question has come up 
about the function of loose or exfoliating bark layers.  What is the 
advantage of loose bark such as found on Shagbark Hickory 
(Carya ovata)?  What is the advantage of exfoliating bark such as 
found on River birch or Paper Birch (Betula spp.)?  Any examples of 
function or references about this topic would be appreciated.

Thanks
Carol

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Carol Auer                      Email: cauer at canr.uconn.edu
Dept. of Plant Science, U-67    Phone: 860-486-1878
Univ. of Connecticut            Fax: 860-486-0682
Storrs, CT USA 06269