A canopy for the future

Faced with climate change and biosecurity threats, which trees are best placed to cope while maintaining their vital role in our ecosytems? Kate Bradbury looks at the science and the solutions

- Kate Bradbury

What is a tree? To you and me it might be a focal point in the garden, a source of shade and privacy, a provider of fruit or even a gift to future generations.

To wildlife it could be home, shelter, a breeding site and something that supplies essential food. To the wider environment, a tree is an essential cog in an ecosystem that sustains life for all. It's part of a community that shares information via a network of fungi and roots. It absorbs and stores water, helping to prevent flooding. It feeds the soil and protects it from erosion, while cleaning the air, removing harmful toxins so we can all breathe more easily. It buffers wind, enabling other plants to grow and insects to feed from those plants, and sheds leaves that a hedgehog or a moth caterpillar might hibernate in.

It might be part of an effort to cool cities. Above all, a tree absorbs carbon dioxide (CO₂), of which there is currently far too much in the atmosphere, causing the increasingly erratic weather we are experiencing, both here and abroad. Could planting more trees help combat climate change? Some would argue it's a bit late for that. But trees can certainly help mitigate the effects of the climate crisis, while providing shade, cooling services and food - for us, wildlife and future generations, too.

The importance of trees, particularly in cities, has not gone unnoticed in government and policy circles. In England, trees outside woodland make up 30 per cent of the nation's tree cover, and a recent satellite and laser mapping project has identified locations where more targeted tree planting can take place. However, successive UK governments' own tree planting goals have been missed - a forest area equivalent to the size of the Isle of Wight has not been planted because governments have not met tree-planting targets since 2020.