Trees, plants and fungi can all provide valuable clues about the age of a forest and how it was used in the past.
Certain plants will only grow in places which have not been disturbed for a very long time. These places must also have constant cover provided by trees. Such plants are natural clues that areas of woodland are ancient (over 400 years old).
Often these clues are difficult to find even for the experts but some are more obvious. In some places in Great Britain for instance, certain flowering plants are good indicators that woodland is old. In the Scottish Highlands, however, these plants can grow in both woodlands and open grassland and so are not very useful.
Instead, it is certain types of lichen, moss and fungi that you need to find. One easily identifiable species is the rare yellow, speckle-belly lichen.
The trees themselves are also clues; you can date them using a method called dendrochronology to find out their age.
The shape of trees today can indicate if they were pollarded or coppiced. These are two woodland management techniques used in the past to grow renewable sources of wood.
Axe marks on the trees can indicate that the woodland was used in the past for wood, or in the case of Puiteachen, to produce fir candles made from the sap taken from the trees.