Measuring Big Trees
Kids will have a grand time measuring a grand tree in their neighborhood.
This article can help children gain an appreciation of the trees around them, by showing them some methods for measuring the girth, height and crown of trees.
Measuring a big tree can be very interesting and exciting. Professionals like foresters, loggers and tree farmers use instruments to measure trees, but you can measure a big one with a few simple easy to come by devices--a yard stick, a pole, a stick and a cloth tape measure.
Once you have located a big tree you want to measure in a park, camp ground, schoolyard or your own yard, assemble your tools and a pencil and notepad for recording figures.
You will need to take three main measurements to judge whether your tree is a champion. First, find the diameter. Start at the ground and mark the bark at 4 and 1/2 feet above ground level. Professionals call this DBH which stands for diameter at breast height. The forester would use a tree caliper or a Baltimore Stick.You can use a cloth or plastic measuring tape. After you have measured the circumference of the tree and recorded this in feet, you can find the diameter by dividing by 3.14.
For illustrations that show how to measure see this American forestry site. Also take a look at a 4-H tree project page to be certain you understand the methods.
The second measurement to take is the height. The pros use instruments called clinometers, altimeters, relascopes, or hypsometers, to measure how tall trees are. You will need a stick that is a long as the distance from your eye to your outstretched hand.
Hold the stick in front of you at arm's length and slowly move backwards from the tree trunk until the top of the tree aligns with the tip of the stick. Mark the ground with your stick or a flag or rock. Now measure the ground from your marker to the tree trunk with your yard stick. That distance in feet should be the height of the tree. This is an approximate measure.
The third measurement is of the tree's crown spread. To find this measurement you must measure the greatest distance between any two points on the drip line. The drip line is the outline on the ground of the outermost leaves of the crown where the tips of the leaves shed rain. Measure that in feet and then move on the drip line to 90 degrees from the line your first measured and measure again. The two figures averaged will tell you the size of the tree's crown spread.
You and your club friends or classmates may want to hold a Champion tree contest in your area. Find out how at this arbor day site. Champion trees must fit certain criteria and must be measured correctly to qualify. Study the 4-H site's list of the nations registered big trees
Find more facts about measuring trees at this tree farming site. I hope you have a large time--beyond measure!
