As I keep mentioning, hedges have a valuable role to play in biodiversity, as they contain such a wide variety of flora and fauna, and provide cover and nutrition for many small animals, whether they be bird, mammal, insect or reptile.
The older the hedge, the more plant species it tends to contain (I’ve posted previously about Hooper’s Law which gives us a way of estimating the age of a hedge based on the number of woody species it contains). Here’s an example my mother found and photographed, a single rural hedgerow in Surrey (near Merrow), showing a wide range of species (with her identifications below):
Beech, viburnum, possibly some privet
Berberis and ivy as well
Possibly some hazel…
And a bit more holly.
Of course that’s before you start looking at the plants at ground level, which are also often fascinatingly diverse, and again can tell us something about the age of a hedge (woodland plants tend to indicate an ancient hedge that was originally created as a remnant when the forest was cleared).