Fire history on the California Channel Islands spanning human arrival in the Americas

Recent studies have suggested that the first arrival of humans in the Americas
during the end of the last Ice Age is associated with marked anthropogenic
influences on landscape; in particular, with the use of fire which would have
given even small populations the ability to have broad impacts on the landscape.
Understanding the impact of these early people is complicated by the
dramatic changes in climate occurring with the shift from glacial to interglacial
conditions. Despite these difficulties, we here attempt to test the extent of
anthropogenic influence using the California Channel Islands as a smaller,
landscape-scale test bed. These islands are famous for the discovery of the
‘Arlington Springs Man’, which are some of the earliest human remains in
the Americas. A unifying sedimentary charcoal record is presented from
Arlington Canyon, Santa Rosa Island based on over 20 detailed sedimentary
sections from eight key localities. Radiocarbon dating was based on thin,
fragile, long fragments charcoal in order to avoid the ‘old wood’ problem.
Radiocarbon dating of 49 such fragments has allowed inferences regarding
the fire and landscape history of the Canyon ca 19–11 ka BP. A significant
period of charcoal deposition is identified approximately 14–12.5 ka BP and
bears remarkable closeness to an estimated appearance age range of the first
human arrival on the islands.