The deforestation of Easter Island (SE Pacific): a review

Abstract

Easter Island deforestation has traditionally been viewed as an abrupt island-wide event caused by the prehistoric Rapanui civilization, which precipitated its own cultural collapse. This view emerges from earlier paleoecological analyses of lake sediments showing a sudden and total replacement of palm by grass pollen shortly after Polynesian settlement (800-1200 CE). However, further paleoecological research has challenged this view showing that the apparent abruptness and island-wide synchroneity of forest removal was an artifact due to the occurrence of a sedimentary gap of several millennia that prevented a detailed record the replacement of palm-dominated forests by grass meadows. During the last decade, several continuous and chronological coherent sediment cores encompassing the last millennia have been retrieved and analyzed, showing a very different picture. According to these analyses, deforestation was not abrupt but gradual and took place at different times and at different rates, depending on the site. Regarding causes, humans were not the only responsible for forest clearing as climatic droughts, as well as climate-human-landscape feedbacks and synergies, also played a role. In summary, the deforestation of Easter Island was a complex process, heterogeneous in time and space, which took place under the action of both natural and anthropogenic drivers and their interactions. In addition, archaeological evidence shows that the Rapanui civilization was resilient to deforestation and remained healthy until European contact, which contradicts the occurrence of a cultural collapse. Further research should be aimed at obtaining new continuous cores and make use of recently developed biomarker analyses to advance towards a holistic view of the patterns, causes and consequences of Easter Island deforestation.