How Many Trees Are There in Britain?

If someone asked you, “How many trees are there in Britain?” you might think it’s a question with a simple answer. Surely someone has counted them all, right?

Well… not quite.

steheap/stock.adobe.com

The Problem

Start with the obvious: forests, parks, and gardens. Count them, and you might get billions. But then the questions start:

• Do hedgerows of tightly packed shrubs and small trees count as trees?
• What about tiny saplings in new developments or private gardens?
• Should recently felled trees be included or excluded?

Estimates range from around 3 billion to more than 4 billion trees, and part of the difference comes down to how you define a tree.

Technology to the Rescue (But It’s Tricky)

Counting every single tree by hand would take forever, so researchers turn to GIS (Geographical Information Systems). Satellite images and aerial surveys help detect forests, orchards, and even urban tree cover.

But it’s not as easy as it sounds:

• Trees under dense canopy can be hidden from above, making them hard to count.
• When tree trunks grow close together, automated systems may mistake multiple trees for one.
• Young saplings or irregular-shaped trees can be misidentified as shrubs.

Even with the latest AI and high-resolution imagery, GIS can only estimate, not count every single tree. But it’s still far faster and more accurate than walking the forests with a clipboard.

Maxar, Microsoft

Why It Matters

Trees do more than look pretty. They absorb carbon, support wildlife, control flooding, and make cities nicer places to live. Knowing how many trees exist, and where, helps plan conservation and planting programs that make a real difference. With GIS mapping, we can take the bigger picture view – estimating not only the number of trees, but also the total carbon they lock away, the areas most in need of new planting, and the regions where trees deliver the greatest environmental and social benefits.

The Future of Tree Planting

Britain is planting millions more trees every year. Projects like the Northern Forest and other national initiatives use GIS to figure out where new trees will do the most good, avoiding conflicts with existing land use and maximizing environmental impact. Soon, there will be even more trees to count – but probably still no exact answer.

Paul Maguire/stock.adobe.com

So, how many trees are there in Britain? The honest truth: we’ll never know precisely. But thanks to science and future planting, there are – and will be – even more than you might imagine.