Saturday, December 1, 2012

Looking for old trees?

 Imagine growing up next to a forest grove with trees this size. Tom Howard (pictured here) had that good fortune and he has been educating others about old-growth forests for decades. This is the Wizard of Oz Memorial Grove named in honor of  Oz author L. Frank Baum who grew up in the area and likely visited the grove.The big red oak shown  above is the largest tree in the 7 acre grove, but it is not the oldest. Ring counts have shown that this large oak is "only" 142 years old. Other, smaller, trees in the grove are closer to 200 years. (Such as the fallen white oak shown below -- with glove for scale -- 198 years.)
 
More reliable than girth, in judging tree age, is the way the bark changes as a tree gets older. This is different for each species. For instance red maples get shaggier, but tulip poplars and some oaks get 'balder' (smoother) near the base. Here I am standing next to an ancient oak that has balding bark.
The best way to judge a tree's age is by looking up. The oldest trees will be very tall -- having reached for the top of the canopy over many years. Relative height seems to be a better indicator of age than relative girth -- but exceptions abound in the forest, as elsewhere. Here is what an old tree over 100 ft. tall looks like:
 
Note how much greater the trunk volume is compared to the branch volume. (Taken with Photosynth app). To the discerning eye, however, it is the 'architecture' of the branches that tell us which trees are truly ancient. Look for tall trees that have fewer limbs, and with limbs that are thick and twisting. When you see "sinuosity" such as that exhibited by the tree below in the North Syracuse Cemetery Oak Grove -- then you know you are walking among the ancients.This tree could be 300 years old.
 
 

1 comment:

  1. Joan, Nice rules of thumb, but I've learned you have to factor in species and whether the tree is open grown. I have/had (just lost one last year) 100 foot Populus grandidentata They are about 80-90 y/o. Same goes for Liriodendron tuliperfera.
    Donald Leopold can tell you of old growth forests in Kentucky I'm sure. We had the same professor for Dendrology and visited some very old forests.

    Keep up your good work.
    Lew Ward

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