Forest list archive: msg00040

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Re: Growth and longevity (was RE: Sustainable Forest Management



Tom

There's a confusion of authors here.  I did not say this! Bob Keeland did.
(No capitals used or implied) Furthermore, I don't believe anybody really
knows whether it's true since so few places in the world have ever been
managed through a whole rotation to determine the effect on growth rate on
longevity.

glenn

>>       On 12/1/95 Glenn Mroz wrote (excerpted from longer message)
>>        I would caution,
>>      however, that large trees that are large through intensive management
>>      of growth rates are not the same as large trees that are large due to
>>      centuries of slow growth.  I am mostly familiar with old-growth
>>      baldcypress that has a very tight ring structure.  Some large diameter
>>      second growth baldcypress have very wide rings in comparison.  It is
>>      well known that trees that grow faster do not live as long, so a
>>      potential problem with "managed" old-growth is that it will probably
>>      not be old-growth for very long.  The dynamics will just not be the
>>      same.
>
>I'm not so sure how well known it is that trees that grow faster do not live
>as
>long.  This is certainly true across species: aspen doesn't live as long as
>oak or Douglas-fir.  But within species (which is what is being discussed
>here),
>I'm not so sure that this is true.  Coast redwood grows at an amazingly high
>rate when young, then slows down.  Intensive management might increase growth
>rate while young, but if these trees are left alone, and assuming they are of
>long-lived species, I'm not so sure that they wouldn't live just as long.
>
>There are some assumptions here: that the wood properties have not been so
>changed
>that the trees would break up under mechanical load; that there no site
>limitations to longevity; and that anyone is going to
>allow intensively managed trees to sit there.  But the main point is still
>valid:
>I don't think we know anything about differences in longevity between fast-
>growing and slow-growing individuals of the same species.
>
>Regarding baldcypress, I have seen some very old baldcypress in W. Kentucky
>which had extraordinarily wide rings when young, and only hit the brakes
>when older.
>
>Cheers,
>Tom Kimmerer
>University of Kentucky
>Kuala Lumpur
>
>




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