A spindly tree of heathland and moorlands, and dry and sandy soils, the Silver birch is well known for its paper-thin, white bark. It is a great coloniser and can quickly spread in an area.

An uncommon tree of wet woodlands, riverbanks and heathlands, Alder buckthorn displays pale green flowers in spring, and red berries that turn purple in autumn.

The Alder fly is a blackish invertebrate, with delicately veined wings that it folds over its body like a tent. It can be found near ponds and slow-flowing rivers; the larvae living in the silt at…

This large skate has tiny, prickly spines all over its back.