How Do You Measure A Tree? Forests
are very big. A forester could not possibly measure every tree in the forest, but by learning about parts of the forest and measuring select trees, it helps them understand the entire forest.
In the early days of forestry, they had to calculate all the information by hand. As they measured a tree, foresters would record information about the tree in a tally book. Using math skills they learned in college, foresters would tally all the information on the trees they sampled.
Today, foresters still use those basic math skills, but they also use computers to help store and analyze information about the entire forest, based on the information they have about single trees. The forester uses a computer to summarize all the information collected out in the woods. They even use computers to: make maps of the forest, estimate how fast a forest will grow, plan when to harvest the trees for products and mark certain forest areas for environmental protection.
Foresters
Use Many Different Tools To Help Measure Trees
cruising vest
Working in the Woods Foresters wear a cruising vest when working in the woods. It has many pockets to hold the forester's tools and is bright orange so that the forester can be easily seen by others, especially hunters, who may be in the forest.
compass
Getting Around the Forest
When the forester is in the woods, he or she needs to know how to get around. Using a compass, foresters determine their location in a forest.
data recorder
Keeping Track of the Forest
After collecting information about the forest, the forester uses a computer to summarize it. New hand-held computers called data recorders.
soil sampler
How Good Is the Soil? The quality of the soil tells the forester how well the tree will grow. A forester may use a soil auger or a soil sampler to pull up soil samples and send them to a laboratory where they are analyzed.
tape measure
How Wide Is the Tree? Foresters use tapes to measure the diameter of a tree. They always measure the diameter at 4.5 feet above the ground. This measurement is called "Diameter at Breast Height."
increment border
Sampling a Tree It’s easy to look at rings after a tree has been
cut, but how do you check growth while a tree is still standing?
Using an increment borer, the forester can pull out a piece of the tree that looks like a pencil. They can then count the rings and see how old the tree is, how fast it’s growing and how healthy it is.
The study of tree time is called dendrochronology. Scientists have found that they can learn about past climates by studying tree ring patterns of very old trees.
clinometer
How Tall Is the Tree? Foresters need to know the height of the tree to understand the volume of wood in the tree. There are many different types of instruments that a forester can use to gauge the height of the tree. One of these tools is a clinometer. It uses geometry to help a forester quickly measure height. Tree diameter such as a tree, and height are used to determine how much usable wood is in a tree.
cross section of a tree
Tree Rings One of the best ways to learn about a tree is to look
at its annual rings. Each growth season, a tree adds a new layer of wood to its trunk,
called tree rings. Looking at these rings with the help of an increment borer, a forester can tell how old the tree is, patterns of
change in the tree's life and changes in the area where it grows.
Each ring has two parts: a wide, light part (early wood) and
a narrow, dark part (late wood). The early wood grows during
the wet spring growing season. During the transition from the
drier summer to fall and winter, growth slows and the late wood
forms.
The rings provide clues about the climate or weather of the area over time. They are thick in years of good rainfall and thin in poor years.
Drought, frost, fire or disease can cause a missing or partial ring.
dibble
Planting the Forest Foresters supervise the planting and growing of new trees, a process called regeneration. They advise on the type, number and placement of trees to be planted. They choose and prepare the site using controlled burning, bulldozers, or herbicides to clear weeds, brush and logging debris.
How Tall Do Trees Grow? Some trees, like redwoods and sequoias, grow to be over 300 feet tall, while some types of junipers may only be 20 feet when full grown. Most trees are not that tall or short; the average tree is 40 to 100 feet tall. A loblolly pine usually grows to be 40 feet tall in 20 years.
