Dev (and Ecolog):
Climate is highly variable from place-to-place, even in the "same" location,
and "all kinds" of site variables can affect tree height and dbh (not to
mention age). Mean annual anything as independent variables are next to
worthless (or worse, misleading) unless you have years, decades, to devote
to the project (and even then they are very questionable), largely because
such variable can vary too much from year to year. DBH is a very crude
measure, and cores are also crude (except for the single tree being cored).
I must be missing something if this is the way "most contemporary studies"
are done. I hope someone can point out the errors of my thinking.
WT
----- Original Message -----
From: "D Chakraborty" <[email protected]>
To: <[email protected]>
Sent: Friday, March 08, 2013 5:51 AM
Subject: [ECOLOG-L] need help
Dear Colleagues
I am working on developing growth response functions to investigate the
effects of climate on growth performance of Douglas fir provenances. Most
of the contemporary studies use multivariate models with tree height at
specific age as dependent variable and climate parameters(eg. Mean annual
temperature, degree days , Annual heat mositure index etc) as independent
variable.
We all know that tree height is least influenced by management and
therefore its most logical to use tree height as the dependent variable.
However in my case I have very little tree height data.
In this circumstance I am looking for your valuable opinion that can
justify the use of DBH as a dependent variable.
Looking forward to hearing from you.
best regards
Dev
--
Debojyoti Chakraborty
Wissenschaftlicher Mitarbeiter
Department of forest and soil sciences, Universität für Bodenkultur Wien
Ph: Vienna +43 6764871296 (m)
Lecturer, Amity Institute of Global Warming and Ecological Studies
Amity University campus, Block D, II floor,Sector 125, NOIDA
India www.amity.edu/aigwes
India +919868001750 (M India), 01204392562 (O) 0120-4392606 (Fax)
alternate email id: [email protected], [email protected]
skype: d-chakraborty
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