Fukugi (Garcinia subelliptica) tree lines were planted along the periphery of properties shaping a green landscape on the islands of the Okinawa Prefecture. Throughout the years, these trees have provided diverse ecosystem services, including wind breaking, home cooling, and air purification. However, in recent decades the trees vanished at a fast pace mainly due to human action. This study aimed at clarifying the present distribution of remnant Fukugi trees and evaluating their habitat and health condition in order to establish conservation and management strategies. A total of 3,052 trees, estimated to be over 100 years old, were found in the three hamlets of Aguni Island: Higashi, Nishi, and Hama. Diameter at breast height, tree height, and orientation were measured and tallied for each tree in 2009. In addition to natural hazards such as typhoons, human activities largely degraded tree habitat and health. Life style changes and population loss in the rural areas are among the major reasons contributing to the decrease of Fukugi trees. Private ownership of woodlands is considered a major limitation to restrict the cutting of old trees. Increasing environmental awareness through the education of village inhabitants will be effective for protecting the old trees and conserving the landscape.