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Recently, the focus of our weekend hikes has changed to keep step with the seasons. We don’t see many insects now, the birds are less in number, and most plants have died back or dried to their leafless winter state. At this time of the year we turn our attention to those things that might best be studied when the trees are without leaves and the ground mostly bare. We study trees, rocks, lichen, bird and wasp nests, and any other objects that are now revealed.

This autumn, we’ve decided to initiate a personal “Big Tree” project as an appropriate seasonal activity. Out of curiosity, I did some checking around online to see if there’s an Ontario-based project. I found a listing of Champion Trees on a website maintained by the Ontario Forestry Association (OFA). There’s also a listing of Ontario’s Oldest Trees. So, it appears that we could submit trees to an Ontario project if we happen to find some good candidates. We’ll keep that in mind, but for now, our goal is simply to locate, measure and record data on the “big trees” that we come across during our walks.

This weekend, we recorded data on our first tree, a Red Oak (Quercus rubra) that we met along the Sylvan Trail at Murphy’s Point Provincial Park. It’s a decent sized tree – we’ve seen larger Red Oaks – but it provided a good chance to practice our tree measuring skills. For guidance, we followed the Nova Scotia How to Measure Big Tree Size webpage instructions. We began by taking a GPS reading of the tree’s location (that’s what Don is up to in the above photo). Next, we measured the circumference of the tree with a measuring tape. It had a circumference of 111 inches at what is referred to as DBH (And yes, we measured in inches as that’s how our construction tape is marked). I shot photos of the tree, its bark, and the leaf mulch around the base of the tree (see leaf shot below).

I then walked to a spot where I could measure the height of the tree by holding the measuring tape at arm’s length in front of me (to see what that’s all about, check out the Nova Scotia big tree measuring instructions. There’s a diagram and formula there that explain how to measure and calculate the height and canopy width of a tree). After I took the measurements, Don paced off the distance from the tree to me — 47.5 paces — and he can do quite an accurate 3-foot pace, so that gave a distance of 142.5 feet. My “height” measurement of the tree was 25 inches with the tape measure held approximately 28 inches from my eye. All measurements and the GPS reading were recorded in the fieldnote book that we always carry on our hikes.

The final step of the process was completed back home at the computer. The 111 inch circumference was divided by pi (3.1416) to calculate an average diameter of 35.33 inches. The height of the tree was calculated by dividing the height I had measured at a distance (25 inches), by the distance between my eye and the tape (28 inches) x the distance from the tree to the spot where I took the measurement (142.5 feet). So, that goes 25 ÷ 28 = .89 x 142.5 = 127 feet (btw, I rounded these numbers off during calculation as there’s not much point in trying to be too precise). The canopy width was measured at 12 inches, so approximately 61 feet across (not counting a weird branch that sort of hung way out to one side). By the way, someone (Wayne?) might want to check my calculations and methodology as, quite frankly, I consider myself to be rotten at math. (-:

So, that was our first foray into measuring Big Trees. It doesn’t seem too difficult. What we hope to achieve through this exercise is to:
* compile information on a number of the big trees that we see in our travels.
* sharpen our skills at estimating the height of trees (my eyeball guesstimate was actually not too shabby).
* give ourselves some motivation to get out and about on our favourite trails over the winter when we are at greatest danger of turning into couch potatoes.
* visit some of our favourite trees and see how they’re doing. I make particular mention of this point as so many of our sylvan friends have fallen victim to various forms of pestilence over the past few years – really ever since the ice storm of January ‘98 – so, this will help us to monitor everyone’s health a little more closely.

After we get a few trees measured, I’ll set up a web-based chart and post the collected data.

So! Have any of you tried measuring trees? If you haven’t done so, do you feel inspired enough to go out and measure a few trees? If so, please do come back and share some data! (-:

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Tags: Big Tree Project, Red Oak, Quercus rubra