Hedgerow dating

Most of the hedgerows present in the British landscape were planted within the last few hundred years but there are examples that are much older. Dr Max Hooper proposed that counting the number of species present in a 30m section and equating each species with 100 years could date hedgerows. Thus if 4 different tree or shrub species were present then the hedge was likely to be at least 400 years old. This theory was formulated after Hooper had analysed a number of hedgerows that had been securely dated due to their inclusion in historical documents. It is advised that in order to obtain an average result 3 different 30m lengths of a hedge should be analysed.

(taken from http://www.lboro.org/~wwatch/Info%20pages/Hedgerow%20fact%20sheets/Ageing%20Hedgerows.htm)