It is an everyday tale of citizen action, but the Woodland Trust's efforts to preserve and restore ancient woodland and show the rest of us why it matters so much are a triumph of what one determined individual can achieve. It is less than 40 years since a conservation-minded farmer, Kenneth Watkins, became alarmed at how swiftly broadleaf woodland was disappearing – sometimes under the plough, more often the developer's bulldozer or the Forestry Commission's hunger for commercial trees. Native woodland is one of those ingredients of biodiversity that looks entirely untended but requires constant vigilance. Intensive farming has led to nitrogen runoff and the flourishing of species like holly, which destroys all but the deepest shade-lovers beneath. Once, coppicing the new growth used to create a range of environments with varying amounts of light. Now the canopy is uniform and the ground beneath shady all summer long. But the Trust and – following its example – many other woodland owners have saved and restored more than 20,000 hectares of woodland across the UK. One such wood is Duncliffe in Dorset, bought by the Trust 25 years ago this autumn – an ancient woodland in Hardy country that is thought to contain the oldest living things in the county (a blow to Bournemouth). It has been rescued from the dreary non-native softwoods, restored partly by volunteer effort, and now it is open all the year round to anyone who wants a stiff turn uphill and, in the spring, a feast of bluebells.