Research Article

Landscape Ecology

, Volume 26, Issue 4, pp 487-500

Modeling impacts of fire severity on successional trajectories and future fire behavior in Alaskan boreal forests

  • Jill F. JohnstoneAffiliated withDepartment of Biology, University of SaskatchewanInstitute of Arctic Biology, University of Alaska Fairbanks Email author 
  • , T. Scott RuppAffiliated withSchool of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks
  • , Mark OlsonAffiliated withSchool of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks
  • , David VerbylaAffiliated withSchool of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Much of the boreal forest in western North America and Alaska experiences frequent, stand-replacing wildfires. Secondary succession after fire initiates most forest stands and variations in fire characteristics can have strong effects on pathways of succession. Variations in surface fire severity that influence whether regenerating forests are dominated by coniferous or deciduous species can feedback to influence future fire behaviour because of differences in forest flammability. We used a landscape model of fire and forest dynamics to explore the effects of different scenarios of surface fire severity on subsequent forest succession and potential fire activity in interior Alaska. Model simulations indicated that high levels of surface fire severity leading to a prolonged phase of deciduous forest dominance caused a reduction in landscape flammability and fewer large fire events. Under low surface fire severity, larger patches of contiguous conifer forest promoted fire spread and resulted in landscapes with shorter fire return intervals compared to scenarios of high surface severity. Nevertheless, these negative feedbacks between fire severity, deciduous forest cover, and landscape flammability were unable to fully compensate for greater fire activity under scenarios of severe climate warming. Model simulations suggest that the effects of climate warming on fire activity in Alaska’s boreal forests may be partially but not completely mitigated by changes in fire severity that alter landscape patterns of forest composition and subsequent fire behaviour.

Keywords

ALFRESCO Black spruce Boreal forest Climate change Disturbance Fire regime Forest regeneration Simulation model Picea mariana