Over 200 plant species are used as ancient woodland indicators. But what does this mean and why are some plants ancient woodland indicators and others not?
What is ancient woodland?
Ancient woodland is land that has been continuously wooded since 1600 in England and Wales or 1750 in Scotland. Ancient woodlands have a high ecological value and can be identified using historic maps and archives for evidence but also by seeing what’s on the ground.
What is an ancient woodland indicator species?
Individual or groups of species can be used as biological indicators. This means that their presence in a habitat can indicate certain environmental conditions.
There are no plants that are only found in ancient woodland. Plants used as ancient woodland indicators are instead those that are more common in ancient than new woodland.
The number and abundance of species in a wood can be used to help assess whether a wood might be ancient.
What makes a plant a good indicator?
Different plants are used to identify ancient woodland around the UK. They all have key characteristics that make them good indicators, including:
- Being slow at colonising a new habitat, so less likely to be in new woodland
- The need for conditions created by stable and continuous woodland cover
- Being less likely to survive outside woodland where they could be more exposed
- Being easily identifiable
Other factors also influence the number of species found in a woodland. These include wood size, site management and structure. Indicators are therefore just one clue to a woods history.
Have you seen any?
Some species are used more than others. Here are some of the more commonly used indicators that you might have spotted: