• Various tools are used to measure and track the growth of trees.Jupiterimages/Comstock/Getty Images
  
  As part of their job, foresters keep statistical records on the trees in the forest. This involves measuring trees and identifying different aspects of individual trees. Foresters still predominantly use basic math skills to measure trees, especially the height, and then enter the data into computers for analysis.
  
  

Tape Measure

• Determining the width of a tree can be as simple as using a tape measure to measure the diameter. Foresters always measure the width of a tree at a height of 4 1/2 feet from the ground, which is called "diameter at breast height."
  
  

Increment Borer

• The rings appearing in the trunk of a tree indicated the tree's age. Rings are readily visible on felled trees, however, foresters use an increment borer on live trees to determine age. These borers are not injurious to trees and allow a small "bore" about the size of a pencil to be extracted from the trunk. The annual growth rings are visible on the bore section, which also gives an indication of the tree's health and growth rate.
  
  

Other Tools

• Foresters measure the height of trees using a number of tools and methods. A clinometer measures the height of the tree using geometry. Other tools include transits, lasers, hypsometers and Abney hand levels. Another method utilizes a stick but requires following a basic procedure. The forester holds the stick vertically with the length of stick above his hand equal to the distance between his eye and hand. While holding the stick in this position he moves away from the tree until the top of the stick appears even with the top of the tree while his hand remains at ground level. The distance between him and the tree is equal to the height of the tree.