This article summarizes some recent research on the topic:
Among Stevens-Rumann,’s work was a 2017 study of nearly 1,500 sites charred by 52 wildfires in the U.S. Rocky Mountains. Her research found that lower elevation trees had a tough time naturally regenerating in areas that burned between 2000 and 2015 compared with sites affected between 1985 and 1999, largely due to drier weather conditions.
More recently, a 2019 study written by her colleague Kerry Kemp found that both Douglas fir and Ponderosa pine seedlings in the Idaho’s Rocky Mountains — just south of B.C. — were also struggling in low-lying burned areas due to warmer temperatures, leading to lower tree densities.
Both studies attribute climate change to be the lead cause of why the trees are struggling to grow back in certain fire-scarred areas.
As a result, some ecosystems will no longer be able to support tree species. Instead they may convert to grasslands, she said.
We’ve talked about this before (for example, here). But I would like to know how this kind of information is being incorporated into long-term planning for timber harvest levels. In accordance with the requirement for sustainability on national forests, we should be assuming forest growth consistent with the natural range of variation, which should reflect the effects of climate change on future forests. What I would expect to be seeing based on this kind of research is reduced area suitable for timber production because it would become too dry, and reduced volume resulting from reduced density, slower growth rates and more frequent fires. “Sustained yield” means that projections of lower future timber yields may lead to reduced near-term volume. I’ve looked at the timber volume documentation for a few forest plan revisions, and I haven’t found anything there about climate change (there’s usually an unconnected section on the effects of climate change somewhere). (Projected timber harvest volumes are not tending to go down in revised forest plans.) Maybe that just requires digging deeper than the public-facing documents or maybe it’s not happening. Does anyone know more about this?