Why are some of Britain’s ancient woodlands failing to regenerate?

To the untrained eye, Monks Wood looks healthy and lush in the summer sun. Hundreds of butterflies dance on the edge of footpaths in the ancient Cambridgeshire woodland, which is rich with ash, maple and oak trees. Birds flit through the hedgerows as they feed. A fox ambles through a forest clearing, before disappearing into long grass.

But for a number of years, it has been clear to Bruno Ladvocat and Rachel Mailes that something is missing. In 2022, Ladvocat, Mailes and their research team from Birmingham University were out sampling when they noticed that the small trees that typically cover the woodland floor were increasingly hard to find.

Today, in the dappled sunshine surrounding the largest trees, spaces that would normally be home to a mass of saplings scrambling for light are bare.