Barro Colorado (Panama) is one of the most studied ecosystems in the world and has spawned advance methodologies now utilized all over the world. This is the first comprehensive census of all plants in a large tropical forest community with practical guidelines on how to census a large area. It provides a detailed account of the methods used to establish the forest - with records for 325,000 individual trees. It also reviews methodologies used at 11 other large plots that are part of the Center for Tropical Forest Science (CTFS) network.