Deforestation of Pacific Islands Driven by a Combination of Land Use, Fire, and Climate

Summary

This is an abstract from the "Entangled Legacies: Human, Forest, and Tree Dynamics" session, at the 89th annual meeting of the Society for American Archaeology.

Remote islands in the Pacific Ocean experienced dramatic environmental transformations after initial human settlement in the last 3,000 years. Human causality of this environmental degradation has been largely unquestioned, but examination of regional records suggests a role for climate influences. Here we use charcoal and stable carbon isotopes from deep soil cores to reconstruct the dynamics of fire activity and deforestation across the Sigatoka River valley on the leeward (dry) side of Viti Levu, Fiji. Fires and pyrogenic patches of grassland predated human settlement by millennia, but the magnitude of fire activity and landscape transformation accelerated with the establishment and expansion of swidden agriculture. Regional comparisons with previous studies in Fiji and elsewhere in Remote Oceania settled between 3200–2900 BP reveal a similar pattern of pre- and post-settlement fire activity and landscape change. Pre-settlement fires generally corresponded to droughts, probably driven by El Niño, often correlating with drought-driven wildfires elsewhere in the region. Post-settlement, charcoal and C4 grasses increased dramatically but nearly all major peaks in charcoal and grasses corresponded to increased El Niño activity. This indicates that fire activity and deforestation were a product of the interaction between swidden agriculture and climate rather than land use alone.

This Resource is Part of the Following Collections

• Entangled Legacies: Human, Forest, and Tree Dynamics   •
• Society for American Archaeology 89th Annual Meeting, New Orleans, LA (2024)

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Record Identifiers

Abstract Id(s): 38022.0