The Macrofossil Record of Biodiversity Change in Lago Savai'i, Upolu, Samoa

Over the past few thousand years, humans have arisen as a significant driving force shaping biodiversity. This is particularly emphasised in the case of small, isolated islands. Multiple phases of human colonisation of Pacific islands have resulted in massive irreparable changes to local ecosystems. First with traditional land use by indigenous Polynesian communities, then the rapid growth and exploitation of natural resources following colonial European settlers. This project analysed the changing ecosystem of Lago Savai?i, based on 4338 plant and insect macrofossils from 151 taxa recovered from a 4.5 metre sedimentary core from Lago Savai?i, Upolu. Four zones covering this record were identified, of which two likely cover the post human arrival period. Significant periods are missing in this core, particularly sediment representing the Polynesian phase. Consequently, there is a lack of expected signs of human arrival including known Polynesian introductions. The first definite evidence of human arrival begins at 25 cm, likely dating to European arrival in the past two centuries. The four zones of this record are fairly similar in terms of interpretation, consisting of a rainforest ecosystem with flora and fauna.