An ecologist and landscape historian with a particular interest in ancient woods, forests and trees, he chairs an International Union of Forest Research Organization’s Working Group, was European Society for Environmental History regional coordinator, and chaired a British Ecological Society research group. For over thirty years he has organized woodland conferences on history, heritage, ecology, and management. The author of 500+ research papers and fifty+ books, he advises national parks, local authorities and conservation bodies on tree and woodland management. He edits the Arboricultural Journal. He works widely with popular media too.