3. Tree-ring reconstructions of climate indices used in Bivariate Event Analyses (BEA) and 20th century records of average annual summer and winter temperature and precipitation from Seven hundred years of human-driven and climate-influenced fire activity in a British Columbia coastal temperate rainforest
2016-10-20T13:52:12Z (GMT) by
While wildland fire is globally most common at the savannah-grassland ecotone, there is little evidence of fire in coastal temperate rainforests. We reconstructed fire activity with a 700-year fire history derived from fire scars and stand establishment from 30 sites in a very wet (more than 4000 mm average annual precipitation) temperate rainforest in coastal British Columbia, Canada. Drought and warmer temperatures in the year prior were positively associated with fire events though there was little coherence of climate indices on the years of fires. At the decadal scale, fires were more likely to occur after positive El Niño-Southern Oscillation and Pacific Decadal Oscillation phases and exhibited 30-year periods of synchrony with the negative phase of the Arctic Oscillation. Fire frequency was significantly inversely correlated with the distance from former Indigenous habitation sites and fires ceased following cultural disorganization caused by disease and other European impacts in the late nineteenth century. Indigenous people were likely the primary ignition source in this and many coastal temperate rainforest settings. These data are directly relevant to contemporary forest management and discredit the myth of coastal temperate rainforests as pristine landscapes.