During the past decade, extreme disturbances such as droughts and wildfires have had a devastating impact on California’s natural environment. A study conducted by UC Berkeley researchers and the United States Forest Service details the specificities of that damage and its effects on the state’s species of wildlife.

The study paid attention to two unique species in the southern Sierra Nevada mountains that face severe transformations in their habitats: the spotted owl and the Pacific fisher. The two species thrive in dense forests with canopy cover, but these ideal habitats are increasingly under threat.

“The more dense a forest is, the more vulnerable it is to disturbance,” said Zack Steel, a research scientist with the Forest Service Rocky Mountain Research Station.

Compact forests, Steel added, make it easier for fires and droughts to spread, consequently endangering the animals inhabiting them.

Considering the effects of the disturbances during the past decade, the UC Berkeley study noted that management efforts are necessary for forest preservation. For example, prescribed burnings aim to rid forest floors of potential wildfire fuel, such as pine needles and fallen trees. Furthermore, in drought season, fewer trees means less competition for water within the forest.

Brandon Collins, a researcher for the study and associate adjunct professor in campus’s Rausser College of Natural Resources, noted a relevant dilemma in conservation and preservation efforts: Tension exists between temporarily placing stress on natural environments versus simply leaving an already struggling forest alone.

“We need to figure out a way to minimize the risks of actively managing these forests, while also being able to do the work we need to increase resilience in the landscape,” Steel said.

To Collins, the long-term benefits of preservation outweigh the short-term losses caused by preservation strategies such as prescribed burnings. While forests and wildlife may be temporarily affected by these tactics, they also ensure that people will be able to enjoy these landscapes for many years to come.

Collins noted the emotional impact from decades of forest damage.

“The word devastating comes to mind,” Collins said. “When you see trees up to 200 ft tall that have been charred all the way up, and everything around them has been burned, that’s where it can hit home.”

The necessary measures to prevent these intensely damaging fires from happening again have been difficult to implement, Steel added, since preservation efforts require large amounts of political energy.

However, Steel said he is hopeful that efforts to enable forest conservation will increase soon.

“These places are really important for our daily lives, even if we don’t see them,” Steel said. “What happens in the mountains affects things here.”