Any water within a woodland, such as streams and ponds, will provide a habitat for different species. Such as frogs, toads, newts, fish, and invertebrates that lay their eggs in water. This increases the overall biodiversity (the number of different species present) of the woodland.

Biodiversity often increases in the area where habitats transition from one type to another as there is a greater variance in resources to take advantage of. This is known as the ‘edge effect’.

The banks of water courses are a good example of this. They allow more light to reach lower layers and increase available ground water.