Hazel wrote:

I have seen a hazel wood, the hazels are growing as tree's rather than
shrubs. How are they made this way as they are normally shrubs ?

Hazels are trees and can grow to around 10 metres
(http://www.treesforlife.org.uk/tfl.hazel.html). The ones you see as
bushes are like that as they are usually coppiced.

Brian