Why can't we leave woodlands in Britain to look after themselves? Why do they need managing in order to survive?
Woodlands, like other habitats, can only look after themselves if they are in balance e.g: when they die and renew themselves in equal measure. In some parts of the world natural processes including death from old age, damage by animals and catastrophes (e.g. insects, disease, flooding, drought, wind, and fire) allow the rebirth of woodland, allowing seeds to germinate and a new generation of trees to grow. This allows in light - an essential stage in the regeneration of a woodland.
But there are no wildwoods in Britain - arguably even in Europe - and every woodland we have has been influenced to some degree by people. We have cleared woodland to grow food, and harvested it for building and heat. Our woodlands have been tamed and the wildlife associated with them adapted to these managed conditions, to the point where they have become largely dependent on manmade change. Add to this the effects of climate change and the advent of invasive species, pests and diseases and we have reached a stage where British woodland is dependent on management to survive and thrive. Sometimes 'management' may mean no action is taken, but this should be a conscious decision taken to achieve environmental benefits.