Drought-stricken and heat-stressed forests are less able to regenerate in the wake of forest fires, making climate change a significant factor in their overall resilience, according to a new study in the journal Ecological Letters.
A finding that researchers first documented during fieldwork in Oregon in 2013 has now been significantly reinforced by a team led by University of Colorado forest ecologist Camille S. Stevens-Rumann. Their study examined the impacts of wildfires on forests in Idaho, Montana, and Colorado, Wildfire Today reports.
After the original Oregon study, the publication noted that “moisture stress is a key limitation for conifer regeneration following stand-replacing wildfire, which will likely increase with climate change. This will make post-fire recovery on dry sites slow and uncertain.”
Now forest ecologists are doubling down on their original conclusion: “Dry forests that already occur at the edge of their climatic tolerance are most prone to conversion to non-forests after wildfires.”
The follow-up study, which covered a wider variety of elevations and climatic zones, found regeneration failures across all forest types. Where the initial research explored the impact of a ferocious wildfire on a single ponderosa forest in the eastern Cascades, Stevens-Rumann’s team examined stands with higher moisture levels. While those ecosystems did not show signs of converting to grasslands, they “may experience a shift in species dominance and a decrease in tree density.”