Habitat for grouse: Conifer removal is critical for sagebrush-dependent species

“We can’t talk about conifer removal and management without talking about sage grouse. They are the currency in this management system,” said U.S. Fish and Wildlife Service Habitat and Population Evaluation Team Member Jason Tack. 

“I had never really thought about sage grouse and conifers until I read a paper published in 2013 that really opened my eyes to the effects of encroaching conifer covers,” Tack explained. “While conifers are low-density disturbances, there is a very high population disturbance.” 

Tack, along with Jason Reinhardt of University of Minnesota, presented a pair of webinars in regards to the effects of conifer cover in rangelands and management practices being used in conifer removal.

Sage grouse effects

“Following initial studies, there has been a lot of work tracking sage grouse behavior in conifer dense areas,” said Tack. 

He explains sage grouse avoid conifers “like the plague” as they are nesting. They will actively avoid areas with as little as three percent cover of conifers. 

“The probability of nest success and brood survival are negatively impacted by increases in conifer cover,” said Tack. “When we look at rates in movement in conjunction with conifers, sage grouse move faster resulting in higher levels of mortality.” 

“Covers as low as 1.5 percent can negatively affect the survival of sage grouse,” Tack noted. “But we can see almost immediate changes to sage grouse populations as we begin to address conifer removal.” 

Tack explained sage grouse will almost immediately move back into an area following conifer removal. 

A global issue 

“Conifer cover issues are not exclusive to the western rangelands,” said Reinhardt. “Woodland expansion is a global phenomenon.” 

Reinhardt explained woody plant expansion affects fire regimes and precipitation patterns. In South America, woodland encroachment is reducing livestock production and sensitive savanna ecosystems in Australia are losing ground to woodlands.

“There are numerous examples in North America,” Reinhardt said. “However, these shifts happen so slowly, it’s hard to notice it happening until it’s an issue.”

“The biggest issue we see here in North America is increasing Pinyon-Juniper (PJ) pines,” said Reinhardt. “PJ woodland expansion occurs at the expense of sage grouse habitat.”

Quantifying management 

Reinhardt explained the objectives of efforts to quantify management of conifers in rangeland habitats. 

“We are looking to assess the management and magnitude of PJ reduction in the sagebrush steppe and illustrate relative distribution of effort and identify opportunities for future management,” Reinhardt explained. “We also want to quantify the relative roles of management and fire in terms of PJ reduction as well as identify key future priorities.”  

Reinhardt noted in the mapping of conifer reduction, they evaluated changes between 2011 and 2013 and then again between 2015 and 2017. 

“In our evaluations of conifer reduction, we looked at partitioning out removal by treatment and wildfire,” said Reinhardt. “We then compared patterns in reduction across states, ownership and priority areas for conservation (PAC).”

“The results of these studies show about a 1.6 percent reduction of woodlands,” Reinhardt said. “Treatment and wildfire barely keep up with an estimated expansion of woodlands between 0.7 and 1.5 percent.”

Successful management

“Fire is important,” Reinhardt stressed. “Fire has a substantial impact on the landscape and is huge in terms of overall PJ reduction.”

“Sixty-five percent of PJ reduction is attributed to management and 35 percent of that is because of fires,” Reinhardt explained. 

“States and PACs have done a great job in working towards reducing conifers, especially in Utah, Oregon and Nevada,” said Reinhardt. 

He explained the common thread for these states is they quickly empowered interested partners within the state. 

“PACs saw 53 percent of reductions overall,” said Reinhardt. “Successful targeting exemplifies the ability to manage landscapes at a scale large enough to benefit important to imperiled species.”

Reinhardt noted a majority of reduction of conifers occurred on Bureau of Land Management (BLM) at 58 percent. 

“A relatively higher percentage of overall PJ cover was reduced on state and local government land,” Reinhardt said.

Future policies 

“The National Resources Conservation Service Working Lands for Wildlife codified to ensure future funding for conifer management in rangelands,” said Reinhardt. 

“Regulatory improvements provide certainty for partners,” Reinhardt explained. “However, there are some categorical exclusions.” 

Reinhardt said there was a desire from partners across the country to share outcomes and replicate their successes. 

“There has to be broad cooperative efforts, which will involve crossing ownership boundaries,” said Reinhardt. “In the future, we need to consider expanding removal efforts outside of PACs, recruiting additional partners and improving documentation and tracking of management efforts of expansion.”

Callie Hanson is the assistant editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.