Max Hooper obituary

Biologist and historian best known for Hooper's Law, used to estimate the age of a hedgerow

Max Hooper, who has died aged 82, was a biologist and historian who pioneered the ecological study of hedges. His best remembered discovery was what became known as Hooper's Hedgerow Hypothesis, or more simply as Hooper's Law. By examining the composition of a large number of hedges across Britain, he realised that there was a strong connection between age and diversity.

As hedges grew older, the number of constituent species increased at a steady rate, a gain of roughly one species every 100 years. Hence you could estimate a hedge's age simply by counting the number of woody constituents over a 30-metre stretch. Hooper would have been the first to admit that his hypothesis does not run to planted hedges, and seems to work better in the south than the north. Nonetheless it has become an important tool of landscape surveyors and is a classic demonstration of the value of historical investigation in science. It has also influenced the more mixed hedgerow plantings of recent years.