Recent trends in wildfire area burned have been characterized by large patches with high densities of standing dead trees, well outside of historical range of variability in many areas and presenting forest managers with difficult decisions regarding post-fire management.
While it is well known that wildfires can greatly contribute to soil water repellency by changing soil chemical composition, the mechanisms of these changes are still poorly understood. In the past decade, the number, size, and intensity of wildfires have greatly increased in the western USA.
High-severity wildfires create pulses of snags that serve a variety of functions as they decompose over time. Snag-related benefits (and hazards) are often linked to specific decomposition stages, but snag decomposition rates and pathways are not well understood in many forest types.
Background: The Nechako River Basin (NRB) is a large, regulated basin in north-central British Columbia, Canada that has been impacted by numerous landscape disturbances, including a severe wildfire in 2018.
Wildfire is a natural disturbance in boreal forest systems that has been predicted to increase in frequency, intensity, and extent due to climate change.
Boreal ecosystems account for 29% of the world's total forested area and contain more carbon than any other terrestrial biome. Over the past 60 years, Alaska has warmed twice as rapidly as the contiguous U.S. and wildfire activity has increased, including the number of fires, area burned, and frequency of large wildfire seasons.
Soil moisture conditions are represented in fire danger rating systems mainly through simple drought indices based on meteorological variables, even though better sources of soil moisture information are increasingly available.
Recently identified post-fire carbon fluxes indicate that, to understand whether global fires represent a net carbon source or sink, one must consider both terrestrial carbon retention through pyrogenic carbon production and carbon losses via multiple pathways. Here these legacy source and sink pathways are quantified using a CMIP6 land surface model to estimate Earth’s fire carbon budget.