Wildfire in a Warming Climate Could Relegate Some Forests to Shrubland

The ability of some Western conifer forests to recover after severe fire may become increasingly limited as the climate continues to warm, according to a new study published today in Global Change Biology, by ?HF Senior Ecologist Jonathan Thompson and fellow scientists from the Smithsonian Conservation Biology Institute (SCBI) and UVA.

Although most of the evergreen trees in the study region are well adapted to fire, the study examined whether two likely facets of climate change — hotter, drier conditions and larger, more frequent and severe wildfires — could potentially transform landscapes from forested to shrub-dominated systems.

As part of the study, which was funded by the National Science Foundation, scientists examined conifer forests in the richly diverse Klamath region of northern California and southwestern Oregon. The Klamath region is a botanical hotspot, home to 29 species of conifers and a suite of plant species that exist nowhere else on earth.

The researchers sampled sites that burned severely in wildfires between 1987 and 2008. They found that, after fire, hardwood trees and shrubs quickly established by either re-sprouting from surviving root systems or growing rapidly from seeds that persisted in the soil. These plants dominated the vegetation for at least the first few decades after fire. Most conifers, on the other hand, were slow to compete, relying on establishment of new seedlings borne by trees in less severely burned patches or from outside the fire perimeter.

Continue reading at Harvard University

Photo by Thomas Link