California wildfires have been incredibly devastating over the last year. With over 33 million acres of forestland often vulnerable due to severe droughts and hotter and dryer temperatures, some areas of the state are prone to repeat burns.
Fire scientist Britta Dyer of the American Forests, a nonprofit conservation organization, says that “Not all trees are good, and not all fires are bad.”
To be clear, “not all fires are bad” refers to smaller, less intense forest fires, which often help remove dead trees and vegetation and could ignite much larger wildfires if left untouched. In addition, smaller burns have also been known to help restore and replenish the natural ecological system of the forest.
But the larger fires that California has been experiencing over the last few years often leave fire scars on an area – reversing the regenerative process of the forest and diminishing all efforts at reforestation. Researchers have also found that seedlings are not guaranteed to regrow in areas plagued by forest fires.
Seedlings typically sprout in the first three years after a large-scale wildfire, and the number of seedlings during that time often predicts how dense the forest will be into the future.
A new study examined 1,500 forests across the Rocky Mountains in five U.S. states, impacted by 52 wildfires between 1985 and 2015. The findings revealed an overall decrease of regrowth with no seedlings growing back in about one-third of the sites.
One of the culprits for this lack of regrowth? Climate change.
“We often think about climate change as something that we’re going to feel the effects of in the future. The truth is wildfires are facilitating those changes happening sooner,” said Camille Stevens-Rumann, lead author of the study published today in the journal Ecology Letters. “And I think that was a really big surprise to all of us to see it even over just a 30-year period.”
While the lack of regrowth seems focused on lower elevations, according to the study, Stevens-Rumann provides a rather grim reality to the situation. “We need to just start accepting that they’re not going to become forests again, unfortunately.”
But something else is going on in nature to help forests better adapt to wildfires. For example, in the previous climate, many Colorado forests were overrun with spruce trees, which often become dry and brittle during extreme heat and drought conditions – an ideal fuel source for forest fires.
However, now aspens – native to Colorado – are beginning to outcompete spruce trees. As deciduous trees don’t burn nearly as fast or as quickly as spruce, Mother Nature is adapting to climate change and helping forests be more resistant to wildfires.
But natural evolution takes time, and it still may be many generations away before Mother Nature herself creates a forest that resists the continual vulnerability of wildfires.