Why does this tree grow like this?

These hazel trees have been coppiced, where the branches and trunks have been pruned back to ground. This is like pollarding but done down to ground level.

Hazel tends to grow with many stems but if left untouched those stems often rot. Coppicing invigorates future growth and encourages the new stems to grow long and straight. Hazel is maintained in this way to provide wood for use in making hurdle fencing, pegs, and other items, and also for charcoal making.

This is a traditional, sustainable method of woodland management.