Historical patterns and drivers of landscape change in Colombia since 1500: A regionalized spatial approach

The extent and the spatial patterns of landscape transformation we observe today are the result of the historic human settlement process, often dating back hundreds or thousands of years. Analyzing and reconstructing those historical patterns helps to advance the understanding of the dynamics and persistence of present-day ecosystems. This article explores this reconstruction by identifying and analyzing historic drivers of landscape change for seven periods between 1500 and 2000, and presents historical land use maps showing major trends and impacts on natural ecosystems. Historic land use maps were built using an ecosystem map of 1998 and a "preclearing" ecosystem map, by constraining the spatial change of transformed areas using data on accessibility to rivers and roads, elevation, slope, moisture availability, and settlement areas. We estimate the transformed area rose from approximately 15 Mha in 1500 to 42 Mha in 2000, and land use changed from cropping in 1500 to predominantly grazing in 2000. Demographic impacts of colonization and the introduction of cattle were major drivers of change, but rates and trends of land cover change varied between regions and from period to period. The most impacted ecosystems have been the Andean and tropical dry forests, with the most recent trends toward clearing of humid lowland forests, especially in the Amazon and Pacific. Some landscapes have been subject to strong human influence continuously for more than 500 years, whereas others have been transformed for less than thirty years. We discuss the relevance of a historical approach for guiding conservation goals, ecological restoration efforts, and research hypotheses. Key Words: Colombia, environmental history, historical land use drivers, land cover change, regionalization.