Documenting 50 years of change in Britain's broadleaved woods.
Climate change. Tree disease. Pollution. Unsustainable deer grazing. Britain's woods have had it tough for the last 50 years.
The Bunce survey, first conducted in 1971, gives an unparalleled insight into the major drivers of change in Britain's broadleaved woodlands, and how these vital habitats are responding.
In the early 1970s, Woodland Trust founder Kenneth Watkins was leading the charge in UK woodland conservation by securing our first ancient woodland site in Devon. At around the same time, another woodland visionary was planning a grand survey of Britain’s broadleaf woodlands – Professor Robert Bunce.
An eminent ecologist, Professor Bunce chose 103 woods across England, Scotland and Wales for an in-depth survey of their trees, shrubs, plants and soil. The survey was repeated in 2001 and we now have a third dataset from 2021, making the Bunce survey one of the longest running woodland vegetation surveys in the world.
The 2021 survey wouldn’t have been possible without financial contributions from our supporters, partners and grant giving bodies.
increase in bluebells
decline in wood sorrel
increase in holly
Credit: Don Brubacher / WTML
While there are now fewer trees making up the canopy in the woods surveyed, the trees are older and larger, leaving fewer gaps for light to penetrate to the ground below. As a result, shade tolerant plants have increased, with bluebells up by 15%.
Credit: DP Wildlife Flowers / Alamy Stock Photo
Some plant species have decreased in the woods surveyed, including wood sorrel, which is down by 14%. However, it's worth noting that changes in species aren't automatically positive or negative – whether a plant becomes a 'winner' or 'loser' depends on its context in that specific woodland ecosystem.
Credit: Ilene Sterns / WTML
Holly increased by 16%, making it more common than hawthorn and beech in the Bunce woods. This is due to climate change, with minimum winter temperatures in the UK trending warmer since the Bunce survey began.
Credit: Andrew Hasson / Alamy Stock Photo
The two main drivers of change in the Bunce woods are pests and diseases (such as Dutch elm disease and ash dieback) and unsustainable deer grazing.
Credit: Ben Lee / WTML
Woods and trees don't just face threats from climate change and development – a simple lack of habitat management can stop them thriving. The woods surveyed show reduced management interventions (such as tree thinning or coppicing), which is linked to woods being shadier. Reintroducing habitat management techniques like these can help light reach the woodland floor and allow different species of ground flora to thrive.
So, what's next? We use research and evidence to underpin our approach to tree and woodland conservation, so studies like the Bunce survey are invaluable. We'll use the data to ensure our approach to woodland management follows what's best for woods, trees, wildlife and people.
The results of the Bunce survey are a treasure trove for anybody with questions about woodland ecology and the pressures affecting our woods. The data is openly available to access on the Environmental Information Data Centre (EIDC) website.
The full Bunce survey report is available through the UK Centre for Ecology and Hydrology.
The current phase of the Bunce project was commissioned by the Woodland Trust, with significant financial contributions from players of People's Postcode Lottery, the David Family Foundation, Welsh Government, Defra and Natural England, and a number of smaller contributions from charitable trusts and individuals.
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State of UK woods and trees
The first-ever report that focuses on the UK's native woods and trees. It outlines their current extent, condition and wildlife value, benefits and threats.
