Botanists and biologists use the same techniques to determine the age of a tree, which doesn't include cutting down healthy trees.

Measure the trees circumference, the forestry measurement for this is: 4 1/2 feet (1.4 metres) above the ground. You need to calculate the radius of the tree, ( diameter= circumference ÷pi). After calculating the diameter, you then have to work out the radius of the tree. After you have both of these figures, you need to allow for the thickness of the bark of the tree. You need to subtract 1/4 inch to 1 inch ( 0.64 to 2.54 centimeters). Look around the area, for similar trees that may have fallen or been chopped down, this will enable you to count the trees rings. An example is if the radius is 25 inches (64 centimeters) and you count the rings 125, therefore the average ring width 1/5 inch (0.51 centimeters).

• Increment borer: which is a specialised tool which is used to extract a section of wood tissue, from a living tree, this causes minor injury to the tree. This enables you to count the rings in the core sample, provides the age of the tree and the growth rate of the tree.

Count whorl which are circular growth of branches in the same spot around the tree, but this only good for pine and fern trees.

The final way is to look for a downed tree, similar in width and height to the standing tree. This will enable you to count the rings of the fallen tree, giving you a good idea of the age of the standing tree.

Prendono un campione cilindrico con una speciale coclea sottile. Il nucleo viene poi rasato per ottenere una superficie piatta e viene passato attraverso un densitometro per contare i picchi di legno estivo e invernale