Human Effects in Holocene fire dynamics of Central Western Patagonia (;44° S, Chile)

The forest-steppe ecotone of the eastern slope of the Andes in Central WesternPatagonia (43?40?–49?15?S, Chile, South America) provides a unique area for assessinglong and short term dynamics between humans and past environments. Central WesternPatagonia was a demographically marginal zone inhabited intermittently and with lowintensity by hunter-gatherers during the Holocene. This paper adopts a novel approachin order to assess the relationship between trends in the archeological, pollen, andcharcoal records. The recognition of temporal and spatial scales in both archeology andpaleoecology is crucial for defining roles in paleofire records. The main goal of the paperis to assess the role of climate and human beings as potential ignitors of wildfires byacknowledging the scales in which they operate and the different roles either one playedin paleofire trends. We investigated a case study in the Cisnes River Valley (CRV) wherethe frequencies and magnitudes of fire episodes—reconstructed from macro-charcoalparticles from the Lake Shaman intermoraine sequence—can be attributed to humanaction, while acknowledging the driving role of climate over broader time scales. TheLake Shaman charcoal record spanning the last 19,000 cal years is compared tothe archeological record starting at 11,500 cal years BP. After comparing paleofires,reconstructed from the charcoal record, with peaks and troughs in the radiocarbonrecord and archeological evidence at local and site scales, we argue that this approachprovides insights for assessing the timing and magnitude of human effects on theenvironment. We examine collation and correlation scenarios for comparative trendsbetween the archeological, pollen, and charcoal records. The correlation of occupationalevents at the El Chueco 1 archeological site and other sites along the CRV with the resultsobtained at Lake Shaman is suggestive of a combination of human agency and climatedrivers in the occurrence of fires during most of the Holocene.