Paul, Ryan: Thanks for the clarification. I should have mentioned that I was using my lifetime experience with bur oak to judge approximate age by growth form characterisitics, and not the size of the tree. In MN we have 175 year old bur oaks that are 8 inches dbh on the Anoka Sand Plain, and others that are 4 feet dbh at the same age on silt loam.
Lee Paul Jost wrote: > Ryan, > > I don't think that Lee was judging by size, but by appearance. I > thought it looked about 170 years old. I used to live in a degraded > bur oak savanna and counted rings on fallen and felled trees whenever > I got the chance. Depending upon growning conditions, the upper > branch mass relative to the main trunk thickness, and the bark > thickness and patterns tend to give pretty decent clues for estimating > the age. There will always be exceptions. In my old 20 acre grove (I > owned 1/5 of it), we had many trees from 120-170 years old that had > diameters that varied from 18-52", but the largest ones happened to be > some of the older ones. The tree in the picture has bark and > branching characteristics that resemble the 170 year olds that I have > seen. There were some older looking bur oaks in the area that look a > lot different than the one in the photo that I think may have been > about 200 or more. All those over about 170 tended to have rotten > centers so that a complete ring count was impossible but had to be > guestimated. > > Paul > > On Tue, Aug 4, 2009 at 9:40 AM, Ryan McEwan <[email protected] > <mailto:[email protected]>> wrote: > > In my view it is virtually impossible to estimate a bur oak's age > by its size, unless you know its whole history. Trees of > identical diameters growing relatively close to one another can be > 100 years (or more) different in age. > > here is some peer reviewed evidence supporting this idea: > > http://academic.udayton.edu/RyanMcEwan/Pub/2008,McEwan_and_McCarthy,JBI.pdf > This is true, in fact, for many species... I was sampling > chinkapin oak with Neil Pederson last fall and we found one tree > that was 400 years old, and on the same site, not far away at all, > a tree that was a bit LARGER in diameter (and crown) that was 150 > years old (250 years younger). > ryan > On Tue, Aug 4, 2009 at 9:26 AM, Lee Frelich <[email protected] > <mailto:[email protected]>> wrote: > > > Mike: > > My guess is about 150-175 years. > > Lee > > Mike Kowalski wrote: > > ENTS, > > > > Here are some photos of a beautiful bur oak not far from > where I live. > > They are from both last December and April of this year. > > > > The tree has a CBH of 414 cm (163 inch). I measured the CS > of it at > > one point, but I can't seem to find the data. I think it was > about 20 > > m. It's on land owned by Camp Rotary. I assume it's been > open grown. > > Anyone want to hazard a guess at it's age? > > > > > > Mike > > > > > > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > ------------------------------------------------------------------------ > > > > > -- > Ryan McEwan > The University of Dayton > http://academic.udayton.edu/RyanMcEwan > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
