This multidisciplinary study examines the strategy adopted by villagers in the Roviana Lagoon, South New Georgia, Solomon Islands, to cope with changing socioeconomic and demographic conditions. The study addresses land use, shifting cycles, land tenure, soil nutrients, subsistence production, vegetation, land cover change, and carrying capacity. The results suggested that even if a society had been integrated into the market economy and introduced cash cropping, they used a small island, which was fertile, mainly for traditional shifting cultivation under customary management. However, they used a large area of the main island for cultivation of potentially risky perennial cash crops for private income. This case suggests that a local society is able to develop a harmonized way of rural development, community welfare, and environmental preservation.