Bernard Castelein / Oak leaves (Quercus robur), Peerdsbos, Brasschaat, Belgium. December

David Woodfall / 'Stag Headed' English oak (Quercus robur) important habitat provided by dead wood for wildlife.Knepp Rewilding Estate, Sussex, England, UK, June.

Ernie Janes / Oak trees (Quercus robur) winter afternoon Southrepps, Norfolk, England, UK, January.

SCOTLAND: The Big Picture / Oak (Quercus robur) saplings in tree guards planted as part of woodland expansion on moorland, Cairngorms National Park, Scotland, UK, July.

Ross Hoddinott / English oak (Quercus robur) ripening acorns, Cornwall, UK, August.

Ernie Janes / Oak tree (Quercus robur) shadow on Bluebells (Hyacinthoides non-scripta) England, UK, May.

Andy Sands / English Oak Tree (Quercus robur) ancient pollard with split exposing hollow interior, London, England, UK, November

Andy Sands / English oak tree (Quercus robur) Split in dead trunk showing red deadwood inside trunk this is a very important habitat of ancient trees for saproxylic insects, London, England, UK, November

David Woodfall / Oak trees (Quercus robur) in flooded field, Severn Valley, Gloucestershire, England, UK, February 2014.

Ernie Janes / Oak (Quercus robur) acorns and leaves, silhouetted on white background.

Colin Varndell / Ripening Oak (Quercus robur) acorns. Dorset, UK October 2010

David Tipling / Oak tree (Quercus robur) in hedgerow, north Norfolk, England, UK. May.