9. Characterizing Contemporary Land Use/Cover Change on Isabela Island, Galápagos

This study evaluates land use/cover change in southern Isabela Island, Galapagos, between 2004 and 2010. Spatial and temporal patterns of land use/cover change in the highland community of Santo Tomas and the adjacent Galapagos National Park (GNP) were quantified using remotely sensed data, an object-based classification algorithm, and post-classification change detection. Information derived from population censuses and interviews with local residents were leveraged to contextualize the land use/cover results. Between 2004 and 2010, agricultural land use and native vegetation cover declined across the study area by 28 %, primarily due to the invasion of guava (Psidium guajava) and conversion to forest and shrub. Guava was the most dominant land cover, and its extent increased by nearly 45 % in the GNP and just over 2 % in Santo Tomas. The population of Santo Tomas declined significantly in the same period, and the proportion of landowners participating in off-farm activities increased. The results of this study indicate that ongoing processes of declining agricultural production and land abandonment, coupled with the spread of invasive plants, are transforming the highlands. The maps and results presented in this study will contribute to an improved understanding of landscape dynamics in the region as reliable and current land use/cover data for the Galapagos Islands are lacking.