One woody species per hundred years, which is roughly reliable
The method
Count woody species in a thirty-metre stretch, excluding brambles and ivy. Each species is roughly a hundred years of hedge age.
Why it works
Hedges accumulate species slowly by colonisation. It is approximate, works better on some soils than others, and is right more often than not.
What we found
Two hedges near the church with nine species, which suggests a medieval boundary. That is now being checked against the tithe map.
