Horizon to Horizon: Improving Habitat at a Landscape Scale

Conservation of the iconic greater sage-grouse takes hard work and partnership across the West. In Idaho's Owyhee County, people have come together around threats to sage-grouse and sagebrush to remove encroaching conifers. Teaming up and combining resources, public land managers, private landowners, and conservation and recreational groups are achieving lasting, landscape-scale results.

The sagebrush biome extends across a vast expanse of the American West, containing millions of acres of habitat for wildlife like mule deer, songbirds, and the iconic greater sage-grouse. Sagebrush country supports livelihoods in ranching and agriculture and provides a multitude of recreational opportunities, from fly fishing to mountain biking to hunting. The encroachment of trees into sagebrush rangelands is threatening this treasured and valuable resource for both people and wildlife.

Although trees can’t walk, they are expanding their territory. Research suggests that  areas containing native conifers within the sagebrush biome have increased 125-625% since 1860  as a result of both infill into low density stands and expansion into previously tree-free areas. As native conifer species, like western juniper (Juniperus occidentalis), expand beyond woodlands into the sagebrush,  they shape vegetation by reducing perennial grass, forb, and shrub cover . These changes can increase the risk of high severity fires and make sagebrush systems less resistant to invasive annual grasses.

Sage-grouse move out when trees move into their shrubby homelands. Conifer encroachment decreases sage-grouse breeding habitat because  grouse actively avoid areas with more than 4% conifer cover , a major problem for these iconic critters. The good news is that strategically removing conifers as they move into the sagebrush benefits grouse in a big way.

 A growing body of scientific research demonstrates how targeted removal of encroaching conifers can benefit sage-grouse and other sagebrush-obligate wildlife and birds . Nesting hens were quick to use habitats made available by conifer removal. After conifer removal, females were 43% more likely to nest near treatments than areas where conifers were not removed. Further, recent work building off these results showed how  sage-grouse population growth rates increased by 12% over the 10 years following targeted conifer removal treatments . Restoration treatments are rarely tied to wildlife population impacts, and these outcomes demonstrate that targeted conifer removal works and is one of the few management actions to strongly and immediately benefit this imperiled species.

Benefits of conifer removal are seen for wildlife species beyond sage-grouse. After conifer removal,  sagebrush-obligate birds including Brewer’s sparrow, green-tailed towhee, and vesper sparrow increased in abundance . Additionally, conifer removal  can result in increased cover and diversity of perennial grasses and forbs  and may  increase water storage, keeping water on the landscape for longer . These changes help to create landscapes that are resilient to future disturbances, like drought and wildfire.

In Owyhee County, Idaho, public land managers, private landowners, and numerous partners have come together to strategically remove encroaching conifers from horizon to horizon. This work builds from a growing body of science showing the benefits of conifer removal to sage-grouse. The Bruneau-Owyhee Sage-grouse Habitat Project (BOSH) aims to remove Western juniper (Juniperus occidentalis) from 617,000 acres. To maximize benefits to sage-grouse, highly targeted conifer removal treatments focus on early stage conifer encroachment within six miles of sage-grouse leks. Progress to date already makes BOSH one of the largest conifer removal efforts in the sagebrush biome.

Ongoing work with university and agency partners documents the impacts of the landscape-scale treatments at BOSH on vegetation, sage-grouse, and other wildlife. The NRCS Working Lands for Wildlife Science Team used the  Rangeland Analysis Platform  (RAP), an innovative tool for analyzing vegetation trends over space and time, to assess how treatments impacted vegetation. Their work helps to monitor changing vegetation productivity and invasive annual weeds, such as cheatgrass, which can threaten sagebrush systems after disturbance. Songbird monitoring by the  Intermountain Bird Observatory at Boise State University  documents songbird distribution trends after treatments and puts them into context with broader regional trends. Graduate students in the  Johnson Lab at the University of Idaho  are taking the lead on additional research on sage-grouse, sagebrush obligate birds, and small mammals. New results from the Johnson Lab  provide guidance on how managers can target conifer removal treatments for greatest benefits to sage-grouse 

The Owyhees can appear to be a harsh landscape, yet their rangelands and close-knit communities are resilient. To achieve large-scale, lasting conservation, a culture of collaboration and trust among those that live and work there has developed over decades. Federal and state partners have remained committed to building trust within this community for well over a decade. Achieving landscape-scale projects like BOSH is not possible without agency and community leadership and investment in partnerships with those that live and recreate within these landscapes.

From horizon to horizon, BOSH is a collaborative conservation effort built around trust and partnerships and developed from the latest science to deliver targeted habitat improvements for sage-grouse and beyond. Through adaptive management and monitoring of outcomes, this project provides a unique opportunity to enhance management practices at large scales across the West. Partners are working together to learn as they go and sharing lessons learned to expand this work across the sagebrush biome, all to conserve, enhance and restore the landscape they call home.