A holiday in the countryside would not be complete without a collection of seashells or pine cones. But with nature coming under pressure from all sides is it okay to gather a few mementoes to remind you of your holiday? Or should we take nothing but pictures to remind us of our time away?
Why are grey squirrels appearing to develop patches of red fur? Does this mean the British woodland favours those with a reddish hue?
Does the mimicry of songbirds give us a hint of the sounds of ancient woodland?
Should we in the Earth's temperate zones be setting an example and planting more trees?
Answering these questions are Dr Anna Lawrence, Head of the Social and Economic Research Group of the Forestry Commission; Professor Philip Stott, an environmental scientist from the University of London and Graham Appleton of the British Trust for Ornithology. The programme is presented by Richard Daniel.
Producer: Toby Murcott
A Pier production for BBC Radio 4.