Woodlands and forests are the homes of many mammals in the UK - both native and introduced ones. Deer and Squirrels are treated as special cases, each with its own web page here.
Some rare and elusive members of our mammalian fauna may have benefited from more plantation forests - the pine marten and wild cat are two examples.
Badgers often have setts in woodland. Special badger gates round forestry fences allow badgers access on their well-trodden paths.
Some mammals may damage growing trees. Young trees can have their bark gnawed off right round the stem by voles, causing the tree to die, particularly where these are planted in long grass which were previously fields. Hares may bite right through young tree stems. Rabbits may chew off the bark from the base of older trees.
The rare common dormouse needs special woodland management, especially coppicing to ensure its recover.
In the RFS Chiltern woods, the Mammal Society studies the introduced edible or fat dormouse from mainland Europe, Glis glis - which can damage tree tops too.
Free-living wild boar are back with us after a prolonged absence. Hunting and habitat destruction wiped out the native wild boar here several hundred years ago - but escaped stock from farms and wildlife collections have re-established wild breeding groups in woodlands in Dorset and in Kent/East Sussex.
And the European beaver may to be reintroduced to its former haunts.
Maybe brown bears and wolves could stage a comeback too!
More: The Mammal Society have useful booklets.
FC Practice Note 3. The Prevention of Mammal Damage to Trees in Woodland. (1998).
S. Hodge & H. Pepper.