The annual exchange of CO2 between forests
and the atmosphere can be profoundly affected by wildfire,
especially in regions like the Pacific Northwest where forest
biomass potential is relatively high. The pulse of carbon
released to the atmosphere by large-scale fire events such
as the Biscuit may reduce the net annual uptake of carbon
by Oregon forests by as much as 25%. Moreover, changes in
the size of detrital pools and age structure of living plants
that result from wildfire can influence the exchange of carbon
between the forest and atmosphere for decades to come. A better
understanding of how wildfire and subsequent salvage practices
affect the transfer of carbon between living, dead, black,
and atmospheric carbon pools is necessary in order to link
disturbance and forest management practices to regional carbon
The scale of recent high-severity wildfire events across
the western U.S. has increased the focus on post-fire ecology
and management. Much of this concern revolves around feedbacks
between multiple fire events closely spaced in time and how
forest ecosystems will respond to altered disturbance regimes
under current trends in climate, fire behavior, and management
objectives. Post-fire logging of burned trees is often presumed
to moderate the feedback between two subsequent fires by reducing
fire-generated fuel loads and thus the potential fire behavior/effects
in the event of a reburn. However, the efficacy of post-fire
logging in reducing fuel loading has never been tested and
its ecological effects, such as potentially altered successional
pathways, are virtually unknown. Moreover, recently burned
areas represent an important type of habitat that many species
of animals have evolved to utilize. Snags (standing dead trees)
provide critical nesting and foraging habitat for birds and
small mammals, and as they decay and fall, create additional
habitat for small mammals and terrestrial amphibians as coarse
woody debris. Removal of the largest wood from a site is likely
to have large consequences for the species of wildlife that
are able to persist there. Post-fire logging is thus likely
to interact with several other management objectives on the
The combination of fires we are sampling allows us to address these research questions:
- Quantify the transfer of carbon between living, dead, black and atmospheric pools resulting from the Biscuit event .
With this information we can describe the pulse of carbon released as a result of the Biscuit and compare that quantity of carbon that exchanged regionally in the same year and historically in the Biscuit perimeter.
- Collect base-line measurements of post-fire carbon pools, vegetation/fuel profiles, and vertebrate composition. With this information we can, in future years, back-calculate the post-fire trajectory of NEP and biotic succession both above and belowground.
- How do communities (vegetation, birds, small mammals)
and fuel structure/potential fire behavior change after high-severity fire
and over early succession?
a. 2-3 year time scale ? (empirical field data)
b. 17-18 year time scale ? (empirical field data)
c. And beyond ? (modeling exercise parameterized with above data)
- How does postfire logging affect the community/fuel/fire dynamics observed in question (1)?
- How do communities (vegetation, birds, small mammals) and fuel/stand structure respond to a repeat fire within 15 years (a.k.a. ‘reburn’ per Brown et al. 2003)? Is it fundamentally different than that following a single fire?
- How does postfire logging influence the response to repeat fire observed in question (3) ?
- What are early patterns of conifer regeneration in a landscape-scale fire?
a. abundance, distribution, composition, associated vegetation
b. early regeneration timing
c. distribution of seed sources in a large mixed-severity burn
d. dominant abiotic and biotic controls on regeneration levels