Hi KM
The fissures at the base of the Birch are quite normal and are just a sign that the tree is getting older. The smooth bark changes to this rough fissuring as the tree ages, often for a long way up the stem. Sycamore also does similar and changes from smooth bark to rough plated after about 60 years. The Beech in the picture looks to have had a large branch or co-dominant stem ripped off. Keep an eye on the remaining trunk, as Beech soon develops rot in large wounds and may become dangerous.
