Posted: Tue Sep 12, 2017 2:35 pm
by Lucas
dbhguru wrote:Lucas

If the forest inventory you cited is claiming the heights of the hemlocks shown are 60 feet, that number is likely to be low by 20 to 30 feet, if not more. Sixty feet is nothing for a mature hemlock. Hard to understand where such a number could come from.

We've measured old growth hemlock in the Porcupine Mtns to slightly under 120 feet. We have similar heights for hemlocks in the NY Adirondacks. Same in New Hampshire. In Massachusetts, we see them up to between 125 and 130 feet. In Pennsylvania, add another 10 to 15 feet. In Ohio, our folks have measured a 160-footer or two. In the southern Appalachians, pre-adelgid, we saw them between 160 and 170 feet with a tiny number over 170. That's pretty much the story of the species in terms of maximum height growth.


I am suspicious as well. I believe the data is 20 years old from aerial photo interpretation. I have seen errors in it before. If someone wants to look at the data I can post the link.

However 100 feet is as likely as high as anything is now here. In the past, 150 foot pines were probable, especially in the Zone 6-7 areas in the SW.

The town says there are large several files I can check for info. I have not done it yet. I do remember seeing a report in the library once that talked about the ecology and trees there. It is not in their database but I will ask.

A while back a forester friend said

There is a similar big tree contest here in Nova Scotia. We score by the diameter at breast height in centimeters (instead of circumference in inches) and the height in metres (instead of height in feet) and don't include the width of the crown, which is difficult to measure. I converted their measurements on this yellow birch and the diameter was 124 cm at dbh and the height was 26.5 m. I won our contest back in the early 1990's with a hemlock that was 31 metres tall and dbh of over 125. It had a flared butt just like this yellow birch. It was near Keji, but outside the park. There was another one about 100 feet away that was 33 metres tall, but only 121 cm dbh !!!! Those were the two biggest trees I have ever seen in this province. I've seen some pretty impressive white pine that branch down low and form several big trees in one, but for single stem trees these were massive.