Why do north-facing hillsides have more trees than south-facing ones?

North-facing slopes in Britain stay cooler and damper, with soil that retains moisture better during summer. South-facing slopes get more sunlight, which warms the soil and increases evaporation, often creating drier conditions that favour grassland or heath over woodland.

Can sheep really prevent trees from growing on a hillside?

Yes, absolutely. If sheep, cattle, or deer nibble every tree seedling back to ground level each year, the hillside will never develop woodland no matter how suitable the conditions are. The difference between a wooded and bare slope often comes down to which side of a fence line you're on.

Why are there no trees above a certain height on British mountains?

Temperature drops with altitude, the growing season shortens, and wind exposure increases, making conditions too hostile for tree growth. Britain's actual tree limits have also been heavily shaped by centuries of grazing, burning, and land use, not just natural factors.

How the Hills Got Here

Why One Hillside Grows Trees and Another Doesn’t

Whether woodland takes hold depends on soil depth, drainage, altitude, exposure, slope direction, grazing and centuries of human land use. Comparing opposite hillsides shows why trees flourish on one while the other remains open.

4 September 20266 min read