Study highlights crucial role of gray wolves in ecosystem
Chloe Baul
(CN) — Gray wolves maintain ecosystem balance in the western United States, researchers say in a new study bolstered by a Center for Biological Diversity lawsuit filed earlier in the week calling for increased federal protections.
In a study published Wednesday in BioScience and led by William Ripple from Oregon State University and the Conservation Biology Institute, researchers explored the significant consequences of losing large predators on ecological communities and functions.
Researchers say gray wolves play a crucial role in the ecosystems of the western United States, and emphasized the profound impacts of their absence on plant and animal communities.
"The absence of wolves can have wide-ranging direct and indirect effects on ecosystems and biodiversity, including changes in elk abundance and behavior, plant communities and mesopredator populations," Ripple said in an email. "After wolf extirpation, there are documented declines in long-term tree recruitment, plant communities and ecological processes."
The removal of wolves has led to an overabundance of ungulates like elk and deer, which heavily browse young trees and vegetation, particularly along rivers and streams. According to the researchers, this over-browsing impacts biodiversity and the health of river areas.
"Decreased recruitment of riparian vegetation along rivers and streams is a particular concern because these are areas of high biodiversity,” Ripple said.
The researchers highlighted the importance of historical context in ecological research, stressing that overlooking the historical presence of large predators could cause researchers to miss crucial factors that influence ecosystem dynamics.
They noted that “shifting baselines” — where degraded conditions are mistaken for the historical norm — could distort assessments of ecosystem function by ignoring the full historical context.
The researchers recommend incorporating this historical perspective into conservation efforts when setting restoration goals.
“Shifting baselines can affect assessments of ecosystem function because the full range of historical conditions are not always considered. We believe that, where applicable, the legacy effects of losing wolves and other predators should be taken into account,” Ripple added. “Alongside other stressors such as fire suppression, invasive plant species and overgrazing by livestock.”
Ripple and his team aren't the only ones seeing the effect of the loss of the wolves.
A coalition of conservation organizations, including the Center for Biological Diversity, the Humane Society of the United States, and the Humane Society Legislative Fund, filed a lawsuit against the U.S. Fish and Wildlife Service and the Department of the Interior on Monday.
They argue that the removal of Endangered Species Act protections has led to excessive hunting and trapping of gray wolves in Idaho, Montana and Wyoming, threatening their genetic diversity and survival.
According to the conservationists, gray wolves were delisted from protection in the Northern Rocky Mountains in 2009, with their status fluctuating due to court challenges and legislative actions. Currently, wolves face varying levels of protection depending on state regulations.
Despite recovery efforts since reintroduction programs in the 1990s, gray wolves now occupy only a fraction of their historical range, primarily in the Northern Rocky Mountains and western Great Lakes regions.
The ongoing hunting policies in states such as Idaho and Montana aim to reduce conflicts with livestock and increase prey populations for hunters. However, conservation groups argue these measures are counterproductive.
“Our findings suggest that conserving wolves and other large predators on public lands may be important if the management goal is to preserve ecosystem structure and function,” Ripple said in an email. “We hope our study will be of use to both conservation organizations and government agencies in identifying ecosystem management goals.”