How climate and vegetation influence the fire regime of the Alaskan boreal biome: The Holocene perspective

Feng Sheng Hu, Linda B. Brubaker, Daniel G. Gavin, Philip E. Higuera, Jason A. Lynch, T. Scott Rupp, Willy Tinner

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We synthesize recent results from lake-sediment studies of Holocene fire-climate-vegetation interactions in Alaskan boreal ecosystems. At the millennial time scale, the most robust feature of these records is an increase in fire occurrence with the establishment of boreal forests dominated by Picea mariana: estimated mean fire-return intervals decreased from ≥300 yrs to as low as ∼80 yrs. This fire-vegetation relationship occurred at all sites in interior Alaska with charcoal-based fire reconstructions, regardless of the specific time of P. mariana arrival during the Holocene. The establishment of P. mariana forests was associated with a regional climatic trend toward cooler/wetter conditions. Because such climatic change should not directly enhance fire occurrence, the increase in fire frequency most likely reflects the influence of highly flammable P. mariana forests, which are more conducive to fire ignition and spread than the preceding vegetation types (tundra, and woodlands/forests dominated by Populus or Picea glauca). Increased lightning associated with altered atmospheric circulation may have also played a role in certain areas where fire frequency increased around 4000 calibrated years before present (BP) without an apparent increase in the abundance of P. mariana. When viewed together, the paleo-fire records reveal that fire histories differed among sites in the same modern fire regime and that the fire regime and plant community similar to those of today became established at different times. Thus the spatial array of regional fire regimes was non-static through the Holocene. However, the patterns and causes of the spatial variation remain largely unknown. Advancing our understanding of climate-fire-vegetation interactions in the Alaskan boreal biome will require a network of charcoal records across various ecoregions, quantitative paleoclimate reconstructions, and improved knowledge of how sedimentary charcoal records fire events.

    Original languageEnglish
    Pages (from-to)829-846
    Number of pages18
    JournalMitigation and Adaptation Strategies for Global Change
    Volume11
    Issue number4
    DOIs
    StatePublished - Jul 2006

    Keywords

    • Alaska
    • Boreal forests
    • Charcoal records
    • Climate change
    • Fire regime
    • Holocene

    Fingerprint

    Dive into the research topics of 'How climate and vegetation influence the fire regime of the Alaskan boreal biome: The Holocene perspective'. Together they form a unique fingerprint.

    Cite this