Variability of tundra fire regimes in Arctic Alaska: millennial scale patterns and ecological implications
Higuera PE, Chipman ML, Barnes JL, Urban MA, Hu FS. 2011. Variability of tundra fire regimes in Arctic Alaska: millennial scale patterns and ecological implications. Ecological Applications. 21(8):3211–3226
Abstract. Tundra fires have important ecological impacts on vegetation, wildlife, permafrost, and carbon cycling, but the pattern and controls of historic tundra fire regimes are poorly understood. We use sediment records from four lakes to develop a 2000-yr fire and vegetation history in a highly flammable tundra region and compare this history with previously published fire records to examine spatial and temporal variability of tundra burning across Arctic Alaska. The four sites span a modern climatic gradient in the Noatak National Preserve, from warmer, drier down-valley locations to cooler, generally moister up-valley locations. Modern vegetation varies from herb- to shrub-dominated tundra from down- to upvalley sites, and pollen data suggest that this spatial pattern in vegetation persisted over the past two millennia. Peaks in macroscopic charcoal accumulation provide estimates of fire event return intervals (FRIs), which did not vary significantly at millennial time scales but did vary across space. Down-valley sites burned relatively frequently over the past two millennia, with median FRIs of 150 years (95% CI 101–150) and FRI distributions statistically similar to those from ancient shrub tundra and modern boreal forest. At up-valley sites FRIs were significantly longer than those at down-valley sites, with a median FRI of 218 years (95% CI 128–285).
- Type
- Journal Article
- Authors
- Higuera, P; Chipman, M; Barnes, Jennifer; Urban, M; Hu, F
- Units
- NOAT
- Keywords
- Alaska, Carbon, Charcoal, Core, Historic Range of Variability, History of fire, Noatak, Paleoecology, Permafrost, Pollen, Sediment, Tundra, Vegetation, Wildfire