Britain in the 1920s planted millions of Sitka spruce trees for timber, but scientists now say the country's forests support far fewer birds, plants, and insects than native woodlands

Picture a single species of tree planted in rows across hundreds of thousands of acres in an entire country. That’s the story of Sitka spruce in the UK, and it seems an enormous number of creatures have quietly made it their home. According to the study ‘Sprucing up the UK’s Sitka spruce (Picea sitchensis) forests: can tree species diversification benefit biodiversity?’ published in Forestry, researchers from the James Hutton Institute and partner institutions spent months reviewing published research and biological records to identify what lives on this tree species and how wildlife might respond to mixed-species planting.

The paper says the researchers first compiled records from across the UK and identified 564 species using Sitka spruce for feeding or shelter, then compared how diversification with 34 other tree species would affect biodiversity and ecosystem function.