1961-63 Area Manager, Cotswold Woodlands Ltd. - Management of private woodlands in Gloucestershire.
1963-64 Research studentship, University College of North Wales. - Research into growth of tree seedlings under different conditions.
1964-67 Senior Planning Assistant, Landscape Section, Staffordshire County Planning Department. - Advice on trees and woodlands, administration of Tree Preservation Orders, and rural development control.
1967-70 Conservation Surveys Section, Nature Conservancy. - Involvement in large-scale planning proposals, regional plans, and land use change.
1970-78 Senior Scientific Officer, woodland research section, Nature Conservancy. (From 1973 this was part of the Institute of Terrestrial Ecology.)
1978-2013 Independent consultant. - Work has included woodland management, ecological surveys, establishment and re-establishment of semi-natural vegetation [e.g. design and establishment of vegetation at Samphire Hoe, Dover, on spoil from the Channel Tunnel], tree surveys, and related matters. Have also conducted workshops for the Arboricultural Association on the use of the Helliwell System for amenity valuation of trees and woodlands, which is the only such system which has been accepted in British courts of law.
© Rodney Helliwell 2014