Exploring landscapes on Easter Island (Rapanui) with geoarchaeological studies: Settlement, subsistence, and environmental changes

My research on Rapanui (Easter Island), Polynesia, provides an assessment of new evidence related to the evolving relationships between the Rapanui people and their island environment. Major research goals included formulating an environmental history, an ecohistory that documents ecological changes; assessing resource use and subsistence, especially as they relate to food production; and evaluating the role of cultivation practices as a major cause and consequence of environmental alteration. I also wanted to examine the development of a cultural landscape on Rapanui.; I use a landscape and multidisciplinary approach. Extensive excavations and statistical analyses enhance a systematic archaeological survey in the Te Niu area on the island's northwest coast. Zooarchaeological (faunal materials), archaeobotanic (pollen and phytoliths), and geoarchaeological studies (soil micromorphology and soil chemical investigations) provide evidence of subsistence activities. I also review ethnohistorical records to provide a historical baseline and then develop a chronology based on radiocarbon and obsidian hydration dating.; I investigate the development of dryland horticulture and the construction of settlements and monumental architecture as they relate to environmental change. Cultivation and husbanding animals caused alteration of the native ecosystem. I document the transformation of a palm savanna environment into a cultural landscape. Field and laboratory evidence demonstrates that conversion of much of my project area from a natural environment to an agronomic landscape was underway as early as the 14th century. Horticulture supported an increasingly populous and ranked chiefly society. The geoarchaeological results demonstrate repeated events of erosion and sedimentation, and these are temporally correlated with land clearing and cultivation. The Rapanui people used innovative horticultural techniques, including selective use of microenvironmentally varied geomorphic features, stone walls, and lithic mulch to successfully modify the island environment for cultivation of introduced plants.