Tools of the Trade Forestry Quiz

What is this increment borer used for?
©Photo courtesy of Ben Meadows Company, Janesville, WI

This tool is used by foresters to:

a) take a tree’s temperature
b) tell how old a tree is
c) drill a tap hole for collecting maple sap
d) collect soil samples

The correct answer is “b.” Have you ever looked at a tree stump and counted the growth rings to tell how old the tree was? Foresters use this tool to estimate a tree’s age without having to cut it down. The hollow drill bit is twisted into the trunk of the tree until it’s halfway through. Then the extractor is pushed into the hollow tube. One twist of the borer cuts out a sample core of wood from the tree. The core comes out with the extractor.

Here you can see Mary Ann drilling the
increment borer into a red pine. Next
the wood core is removed using the extractor.

The forester counts the growth rings along the edge of the sample core to estimate the tree’s age. We can also tell how fast or slow a tree is growing by how close or far apart the growth rings are. This process does cause a small injury to the tree, which heals quickly. Here you can see Mary Ann drilling the increment borer into a red pine. Next the wood core is removed using the extractor. Can you see the darker growth rings along the edge of the sample core?

On to the next question...