Measuring Trees

16 Jul Measuring Trees

Why measure trees and their pits?

The size of a tree’s trunk and pit is key to determining the health of the tree. A tree with a larger trunk is able to transport water and nutrients up the tree better. A tree with a spacious pit has more room for its roots to grow and absorb water.

Measuring Trees

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When measuring trees, rather than relying on the measure of a tree’s height or the width of its leafy canopy, trees are measured by their caliper. Caliper refers to the diameter of a tree’s trunk. 

How to measure the Diameter of a tree trunk:

To find the diameter of the tree trunk you must first stand at breast height to the tree. The distance from your breast to the base of the tree is what is called the DBH, or Diameter at Breast Height. If you’re working with young children, or anyone with a mobility challenge, aim for 4.5 feet.

Use either a specialized diameter measuring tape or just any soft measuring tape you can find to measure the circumference (all the way around the tree). If you’re using a regular measuring tape, you can calculate the diameter based on the length of the circumference. Use the formula:

Diameter = Circumference / 3.14

Measuring multi-stem trees

If the tree is two or more trees that have their trunks pressing together, measure the largest trunk. 

If the tree that is a single tree, but splits below 4.5 feet (DBH), you measure at the narrowest point between the split and the ground. 

If the tree is a single tree and the split is above 4.5 feet, we measure the trunk at 4.5 feet.

Measuring the pit

A tree pit is an underground soil area for tree roots. Tree pits are essential for the growth and survival a tree in an urban environment. They give the tree room to spread its roots to gather water and nutrients. According to Jersey City Forestry standards, a tree pit should have an exposed planting area 5 by 5 feet.

Record the date

Recording when you made your tree measurements is very important to understanding the current health of the tree. In the urban environment there are many factors that can influence the overall health of a tree at any time. So it is important to stay updated.

Some things to look out for when measuring the trees:

Scars in the trees from old rooting limbs can skew the measurement by getting in the way of the tape. 

Large lumpy parts of the tree called Burls also can get in the way of your measurement

Identifying the health of a tree:

Measure the health of a tree using a scale from 0 – 3. Use “Zero” for empty tree pit, “One” for  dead trees and “Three” for full, vibrant, healthy trees.

Identify the health of a tree by looking at:

1) Large scars, rotten branches, and signs of fungus at the base of the tree. These are signs of unhealthy trees.

2) The color of the leaves are also good indicators of a tree’s health. Typically, healthy trees have vibrant, sturdy, and green leaves.

3) Look for concrete or bricks that have gotten tangled in the roots. These can hinder the tree’s ability to absorb water and nutrients. 

Geo-locating trees – Finding longitude and Latitude 

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