Quote:
Originally Posted by atula  |
That's more of what we would call a "guess", but it can be far from correct with some trees.
What you read there, is similar to what I did for the Catalpa? Did you read the page in the link I posted?
But I had an advantage - I did a core sample as well, and most of the growth rings were approximately the same size from year to year. Also, I was able to take a core 14" deep, and only need to estimate for the remaining 3".
In Oregon, I volunteered at a demonstration forest Magnus Tree Farm for the World Forestry Center - my friend was the curator. He showed me a cross-cut piece of a Douglas fir tree. It would have been about 20" diameter while standing.
The inner (and older) 10" or so of diameter, had about 80 growth rings. And the rest, or younger 10" of diameter (outer) showed about 30 growth rings.
Why, is unknown. It could have been shaded for nearly a century, then surrounding trees were removed. The point is, without a core sample from a tree like that, measuring diameter is totally unreliable.
It can be more reliable for trees that have been growing alone out in the open, but if the trees are quite old, we may or may not know whether they were within dense forests centuries ago, etc..