Many of Britain's trees have stood the test of time for decades and even centuries. By measuring trees we can compare the findings and learn more about our trees. Measuring trees is easy to do and requires little equipment. If you join a society or association you can start submitting your findings today!

Why Measure Trees?

As trees come and go many have not been documented and will become forgotten despite the fact that they are such breathtaking presences. By keeping records of trees and tree growth in general we can start to monitor trends in successful and less successful areas.

As we find out more about environmental factors effecting trees we can learn how to preserve them better. Associations exist in Britain which catalogue and compare people's findings. In keeping records and comparing them we can display the results and allow people to compete over their finds. This friendly competition in turn encourages people to go out and enjoy the countryside and our trees in general.

Measuring Trees

When measuring trees there are two main measurements to take into account;

• The girth of a tree increases each year and can be used to help identify the age of a tree. This is particularly noticeable in the early years of a trees development.

  Girth is essentially the same as the diameter of the tree trunk. You can measure the girth of a tree effectively using a tape measure. It may take a few attempts to get an accurate reading particularly around a wide tree.

  When measuring the tree take your measurement at least a metre and a half above ground level. If the tree has any swellings or burrs around the one and a half metre mark you may need to compensate for the difference. Make several measurements below this mark at regular intervals and use the smallest measurement to record. Trees which appear even from the outlook may have variation in girth so if in doubt take several measurements.

  If the tree you are measuring forks out below a metre and a half you should record the measurement from the narrowest part and record the height the tree forks at.

  If the tree is positioned on a slope then always take the measurement of the upper side of the tree. Bear in mind that uneven ground or erosion may affect the accuracy of your measurement so make sure to check the surrounding area well for any irregularities. If the tree leans to one side then the measurement should still be taken from the same place but from the lower side of the tree. This method also works for collapsed trees which are still growing.

• The other key measurement of the tree is its height. You can use a clinometer to gain a measurement of the height. Ensure any apparatus you are using is accurate by testing it on a structure you know the height of.

  When measuring the height of the tree make sure to stand a distance away which is at least the length of the tree. Use a tape to mark a baseline stemming from the centre of the tree and make sure to measure on level ground. Measurements can be taken on a slope but the baseline will need to be adjusted proportionately.

  If possible try recording the height from different sides of the tree using different baselines. If your results vary than find the average and use this height.