The height of a tree is the vertical distance between the base of the tree and the tip of the tallest branch of the tree. The height of individual trees in an area indicates different stories of vegetation. Depending upon the different stories of trees in a forest, it is called a multi-storey forest. There are different ways of measuring the height of trees which are broadly classified into non-instrumental methods (i.e. without using any instruments) and instrumental methods (i.e. using instruments).
Clinometer is an instrument used to measure the angle of any tall object. The angle measured is used to calculate the height by applying the principle of right-angled triangle. By using clinometer and simple calculation method we can also track the growth of trees by estimating their height from time to time and through that we can also determine the comparative growth rate of different trees
● Clinometer
● Measuring tape
● Tangent table(You can paste it behind the clinometer or keep it separately) Make your own clinometer by referring to the above picture - Take a graph paper and draw an arc on it from one corner so that the arc joins two right angle sides.
Mark the arc from zero to 90 degrees like a protector.
● Take a colored straw and stick it on the edge where the right angle arc is ending.
● Make a small hole at the corner of the arc and tie a strong cotton thread in it.
● Take a small weight (a small stone or metal bolt) and tie it to the free end of the string.
● Alternatively, you can take a printout of the above picture and fix the colored straw, string and weight as shown
1- Choose a tree whose height is to be measured.
2- Find a place from where the top of the tree can be seen.
3- Look at the top of the tree through the clinometer drinking straw.
4- Read the degrees of the angle by noting the number on the clinometer sheet where the thread crosses the arc.
5- Measure the horizontal distance of you from the tree whose height is being measured.
6- Measure the height of your eyes from the ground.
7- Look up the tangent value of the angle in the tangent table.
8- Calculate the height of the tree by applying the principle of right-angled triangle.
From the angle of elevation, the height of your eye and the distance between you and the tree you can calculate the height of that tree using a simple equation -
X = Y x tangent Z + W
Here, X = Height of the tree
Y = Distance from you to the base of the tree
Tangent Z = Tangent of the angle where the thread crosses the arc on the clinometer
W = Height of your eyes from the ground
You can record field observations and results of the respective calculations for different trees in a data format. An example of a data table is given here; you can design a data table as per your convenience.
● you can calculate the height of different trees and present your finding in the form of mathematical or statistical analysis.
● By calculating height of various tree species in an orchard or forest you can also make inferences of the average story classes in it.
● You can also make inferences which tree species commonly have very high height and which have short height. You can also categorize tree species into different height categories.
● Clinometer is a handy combination tool which is useful for finding the height of trees.
● The height of different trees in an area reflects different stories of vegetation.
● We can also track the growth of trees by estimating their height from time to time with the help of clinometer.
● How will you estimate the height of a tree if you cannot be at the same level at which the tree is standing?
● How will you find the height of a tree if the tree is tilted?
