Tree Survey

Tree Survey Gadget

Next Saturday at the Tree Planting we want to show people what the tree survey is about, so we’ll be displaying some of the data and doing little demonstrations of tree identification. One of the more challenging parts of surveying a tree is calculating its’ height. There are various ways of doing this ranging from finger estimates to fancy gadgets. The typical method involves calculating the vertical side of a right triangle. The easiest of those methods involves sighting a 45 degree line from the ground to the top of a tree. A viewing angle of 45 degrees means that the horizontal distance to the tree base is the same as the vertical distance to the tree top.

triangle

A fixed viewing frame is easily cobbled together. I used a tent pole, a scrap of polycarbonate, two angle brackets and some fishing line. The result is called a clinometer, or inclinometer. This one works by setting the post in the ground and looking for the top of a tree through a viewfinder.

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The post must be vertical, which is accomplished with a plumb line or spirit level. Once it is in place, I measured between the bottom of the sight line and the tree.

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I calculated this Scots Pine to be 58 feet tall. It’s probably within 3 feet either way.

While I was there, I photographed the number tag, the bark, some leaves (needles) and some cones. These images are going into the online tree survey database where they can be used freely by anyone interested in tree identification.

scots pine grid

The idea is that every species of tree in the park should have at least six photos: the tree in profile, the bark, a bud, leaf, flower and fruit/seed. Work on the database is currently under way, and the first results will be online within the month.

The tree surveying has been done by volunteers, and you are welcome to join in. Some 300 trees have already been measured, but we still need photographs, some trees need tags, and the data needs preparing. If you would enjoy doing any of the above please come along to the tree planting or the next survey.

2 Comments

  • Bluebell

    Archive link is broken.

    The park needs a path all the way around so people choose it for walks. Having to re-trace your steps is not so enjoyable.

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