As a plant ecologist by training Lawrence has been researching native plant conservation for more than 20 years. Working on urban greening, arboriculture and tree management since 2003 he is a member of the Old and Valuable Tree Expert Group of LCSD; member of the Community Involvement Committee on Greening of the Home Affairs Bureau and Vice Chairman of the Hong Kong People’s Council for Sustainable Development. He is also a Certified Arborist and is the head of the HKSAR Development Bureau (Works Branch) Tree Management Office.