Vegetation Response to a Short Interval between High-Severity Wildfires in a Mixed-Evergreen Forest. Donato, D. C.; Fontaine, J. B.; Robinson, W. D.; Kauffman, J. B.; and Law, B. E. 97(1):142–154.
Vegetation Response to a Short Interval between High-Severity Wildfires in a Mixed-Evergreen Forest [link]Paper  doi  abstract   bibtex   
[::] Variations in disturbance regime strongly influence ecosystem structure and function. A prominent form of such variation is when multiple high-severity wildfires occur in rapid succession (i.e. short-interval (SI) severe fires, or 're-burns'). These events have been proposed as key mechanisms altering successional rates and pathways. [::] We utilized a natural experiment afforded by two overlapping wildfires occurring within a 15-year interval in forests of the Klamath-Siskiyou Mountains, Oregon (USA). We tested for unique effects of a SI fire (15-year interval before 2002 fire) by comparing vegetation communities 2 years post-fire to those following a long-interval (LI) fire ($>$ 100-year interval before 2002 fire) and in mature/old-growth (M/OG) stands (no high-severity fire in $>$ 100-year). [::] Nearly all species found in M/OG stands were present at similar relative abundance in both the LI and SI burns, indicating high community persistence through multiple high-severity fires. However, the SI burn had the highest species richness and total plant cover with additions of disturbance-associated forbs and low shrubs, likely due to a propagule bank of early seral species that developed between fires. Persistence of flora was driven by vegetative sprouting, on-site seed banks, and dispersal from off-site seed sources. Several broadly generalizable plant functional traits (e.g. rapid maturation, long-lived seed banks) were strongly associated with the SI burn. [::] Sprouting capacity of hardwoods and shrubs was unaltered by recurrent fire, but hardwood/shrub biomass was lower in the SI burn because individuals were smaller before the second fire. Conifer regeneration densities were high in both the SI and LI burns (range = 298-6086 and 406-2349 trees ha-1, respectively), reflecting similar availability of seed source and germination substrates. [::Synthesis] SI severe fires are typically expected to be deleterious to forest flora and development; however, these results indicate that in systems characterized by highly variable natural disturbances (e.g. mixed-severity fire regime), native biota possess functional traits lending resilience to recurrent severe fire. Compound disturbance resulted in a distinct early seral assemblage (i.e. interval-dependent fire effects), thus contributing to the landscape heterogeneity inherent to mixed-severity fire regimes. Process-oriented ecosystem management incorporating variable natural disturbances, including 'extreme' events such as SI severe fires, would likely perpetuate a diversity of habitats and successional pathways on the landscape.
@article{donatoVegetationResponseShort2009,
  title = {Vegetation Response to a Short Interval between High-Severity Wildfires in a Mixed-Evergreen Forest},
  author = {Donato, Daniel C. and Fontaine, Joseph B. and Robinson, W. Douglas and Kauffman, J. Boone and Law, Beverly E.},
  date = {2009-01},
  journaltitle = {Journal of Ecology},
  volume = {97},
  pages = {142--154},
  issn = {0022-0477},
  doi = {10.1111/j.1365-2745.2008.01456.x},
  url = {https://doi.org/10.1111/j.1365-2745.2008.01456.x},
  abstract = {[::] Variations in disturbance regime strongly influence ecosystem structure and function. A prominent form of such variation is when multiple high-severity wildfires occur in rapid succession (i.e. short-interval (SI) severe fires, or 're-burns'). These events have been proposed as key mechanisms altering successional rates and pathways.

[::] We utilized a natural experiment afforded by two overlapping wildfires occurring within a 15-year interval in forests of the Klamath-Siskiyou Mountains, Oregon (USA). We tested for unique effects of a SI fire (15-year interval before 2002 fire) by comparing vegetation communities 2 years post-fire to those following a long-interval (LI) fire ({$>$} 100-year interval before 2002 fire) and in mature/old-growth (M/OG) stands (no high-severity fire in {$>$} 100-year).

[::] Nearly all species found in M/OG stands were present at similar relative abundance in both the LI and SI burns, indicating high community persistence through multiple high-severity fires. However, the SI burn had the highest species richness and total plant cover with additions of disturbance-associated forbs and low shrubs, likely due to a propagule bank of early seral species that developed between fires. Persistence of flora was driven by vegetative sprouting, on-site seed banks, and dispersal from off-site seed sources. Several broadly generalizable plant functional traits (e.g. rapid maturation, long-lived seed banks) were strongly associated with the SI burn.

[::] Sprouting capacity of hardwoods and shrubs was unaltered by recurrent fire, but hardwood/shrub biomass was lower in the SI burn because individuals were smaller before the second fire. Conifer regeneration densities were high in both the SI and LI burns (range = 298-6086 and 406-2349 trees ha-1, respectively), reflecting similar availability of seed source and germination substrates.

[::Synthesis] SI severe fires are typically expected to be deleterious to forest flora and development; however, these results indicate that in systems characterized by highly variable natural disturbances (e.g. mixed-severity fire regime), native biota possess functional traits lending resilience to recurrent severe fire. Compound disturbance resulted in a distinct early seral assemblage (i.e. interval-dependent fire effects), thus contributing to the landscape heterogeneity inherent to mixed-severity fire regimes. Process-oriented ecosystem management incorporating variable natural disturbances, including 'extreme' events such as SI severe fires, would likely perpetuate a diversity of habitats and successional pathways on the landscape.},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-3788803,~to-add-doi-URL,biodiversity,disturbances,evergreen,fire-severity,forest-resources,mixed-forests,postfire-impacts,postfire-recovery,species-richness,united-states,wildfires},
  number = {1}
}
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