As the oak tree grows, the canopy naturally thins itself out and reaches out towards the light, to ensure that even the smallest of twigs get plenty of light. This is particularly the case for trees growing close together, in a woodland setting, rather than on their own in the middle of an open field.
Relevant image keywords:
back lit, bare, bare branches, beauty in nature, blue, blue sky, botany, branch, branches, canopy, common oak, countryside, deciduous, deciduous tree, denuded, english oak, english oak tree, field, frosty, land, landscape, lone, lone tree, lonely tree, naked, nature, no leaves, no people, oak, oak tree, one, one tree, outdoors, plant, quercus, quercus robur, robur, rural scene, scenics, silhouetted, single, sky, solitary tree, sunny, tranquil scene, tree, tree canopy, tree trunk, trunk, twiggy, twigs, vertical, view, winter, woodland
