Sagebrush in Western North America: Habitats and Species in Jeopardy

I n s i d e Hit From Above and Below ...... 2 A Sage Icon ...... 3 Restoration Potential ...... 4 A Glimmer of Hope? ...... 4 FINDINGS issue ninety one / march 2007 “Science affects the way we think together.” Lewis Thomas

SAGEBRUSH IN WESTERN NORTH AMERICA: HABITATS AND SPECIES IN JEOPARDY

i n S UMMA R Y

Sagebrush habitats are declining rapidly across western North America, with over 350 associated plant and animal species at risk of local or regional extirpation. The sagebrush ecosystem is one of the largest in the United States, and it is vulnerable to a litany of threats. Chief among them is invasion of cheatgrass into the understory, followed by high- severity fires that cheatgrass promotes. The expansion of pinyon-juniper woodlands into sagebrush habitat and other

M. Wisdom human impacts, such as overgrazing by The sagebrush ecosystem is one of the largest ecosystems in the United States. It is also considered livestock and energy development, are highly imperiled. also major sources of concern. Regional studies of sagebrush habitats during the 1990s and 2000s conducted “Peel the outer skin, and surprises Sagebrush ecosystems once encompassed in the interior Columbia Basin, the lurk beneath first impressions. up to 150 million acres—virtually half of the American West. They were home to sage Great Basin, and the Wyoming Basins The landscape reveals itself… grouse, pronghorn, and collared lizards. In have identified areas with high potential The Great Basin reminds us the past century, this ocean of sagebrush was for conservation and restoration, as to take nothing for granted.” degraded from all sides and much of it trans- well as those areas most vulnerable to —Stephen Trimble, The Sagebrush Ocean formed into rangelands, whose primary utility degradation. The resulting maps and was livestock grazing. And alas, sagebrush analyses have provided scientists with ne of the largest ecosystems in the isn’t palatable to cows. new methods of landscape analysis and United States is suffering a death by It wasn’t until the 1980s that attitudes toward provided managers with information O a thousand cuts. Alhough it may be sagebrush really started to change. Before then, for conserving and restoring sagebrush hard to imagine, we are witnessing the col- it was routinely “improved,” meaning: dug up, habitats and species. The analyses lapse of the American sagebrush ecosystem. chained, burned, or sprayed with herbicides to have also examined the efficacy of sage Invasive species, overgrazing, fire suppres- make room for better cattle forage—crested grouse as an “umbrella species” for sion, and many other insults have combined wheatgrass, usually. Just about the same time to bring this habitat to its knees. Now, hun- the conservation of other sagebrush- that sagebrush was being reconsidered as a associated species. Findings suggest dreds of species are imperiled, and only the valuable native species as opposed to a weed, that although some species would benefit most dedicated campaign of conservation it was also discovered that intact sagebrush from this approach, many would not. and restoration can secure their future. habitats were disappearing fast, and reversing their decline would be a Herculean task. “The ills of the sagebrush ecosystem are well documented,” says Michael Wisdom, a wild- K EY FINDINGS life biologist at the PNW Research Station in La Grande, Oregon. “It is considered to be one of the most imperiled of all ecosystems in • More than 10 million acres of existing sagebrush habitat in the Great Basin are at the United States. Millions of acres have been moderate or high risk of displacement by cheatgrass. More than 2 million acres of converted to agriculture, cities, roads, energy existing sagebrush in eastern Nevada and western Utah are at moderate or high risk developments, exotic plants, and woodlands. of displacement by pinyon-juniper woodlands. Worse yet, management intervention has been ineffective at even abating the loss, let alone • Moderate to strong habitat declines for sagebrush-associated species have been reversing it.” documented for nearly half of the watersheds in the interior Columbia Basin. Declines are associated with grazing, invasion of exotic plants, altered fire regimes, “Even though you can see sagebrush every- and conversion to agriculture. where,” says Mary Rowland, a wildlife biologist, also based at the Station’s La • Despite declining habitat trends for many sagebrush species, potential exists to Grande Lab, “less than 10 percent of the conserve and restore native sagebrush where large-scale loss and degradation have remaining habitat is unspoiled, in terms of not yet occurred. Intensive management practices, however, are needed for sufficient historical structure and composition. As a restoration in many areas. result, more than 350 plant and animal species are at risk of local or regional extirpation.” Working right in the heart of sagebrush The approach taken by Wisdom, Rowland, “The first time anybody really looked at country, Wisdom and Rowland for the past and their colleagues has involved broad-scale this ecosystem—about 15 years ago in the 10 years, have been investigating the decline modeling of environmental conditions on interior Columbia Basin—it was clear that of sagebrush habitat and species. They have both public and private lands. Sophisticated the status and trends of species in sagebrush collaborated on several major landscape vegetation simulation models designed to run habitat mirrored those of other species in analyses including the Interior Columbia on millions of acres, and literally hundreds other ecosystems that were already listed Basin Ecosystem Management Project, the of state-and-transition models, were used to as threatened or endangered. This sparked Great Basin Ecoregional Assessment, and the assess past and current conditions, and to a widespread change in research and Wyoming Basins Ecoregional Assessment. predict effects of future land management management thinking about the ecosystem’s These projects have transformed perspectives scenarios on sagebrush and grassland- status, particularly because conditions were regarding sagebrush habitat and have provided associated vertebrates in the interior not predicted to improve,” says Rowland. managers with information for conserving and Columbia Basin. restoring sagebrush.

Hit from above and below f you had to pick just one, cheatgrass intense fire. Cheatgrass exploits that charac- invasion is perhaps the greatest threat teristic to get the competition out of the way. I to sagebrush habitat. A scourge to land It then relies on its tremendous seed produc- managers, this exotic annual grass has been tion to fill in the gaps, eventually creating reshaping the West since the late 1870s, when monocultures of cheatgrass. it arrived from Eurasia. The name cheatgrass is a reference to its life history strategy, which uses a headstart early in the spring, thereby Purpose of PNW Science Findings outcompeting native grasses for needed water To provide scientific information to people and nutrients, and “cheating” livestock out of who make and influence decisions about valuable forage. managing land. “Cheatgrass can live out its entire life cycle PNW Science Findings is published in just a few weeks in spring,” says Wisdom. monthly by: “After that, it’s useless as forage and becomes Pacific Northwest Research Station a dangerous fuel-bed for wildfire. By mid- USDA Forest Service summer, it is tinder waiting to fuel a high- P.O. Box 3890 severity fire, which can kill the overstory Portland, Oregon 97208 sagebrush and clears the way for more (503) 808-2137 M. Rowland cheatgrass in following years.” Send new subscriptions and change of address A variety of land uses and undesirable processes information to [email protected] pose a threat to sagebrush habitats and species Cheatgrass perpetuates itself through fire. of concern. Many native species of sagebrush, forbs, and Sherri Richardson Dodge, editor [email protected] bunchgrasses are not adapted to frequent, Keith Routman, layout [email protected] Science Findings is online at: http://www.fs.fed.us/pnw/ United States Forest The site includes Science Update—scientific knowledge for pressing Department Service decisions about controversial natural resource and environmental issues. of Agriculture

2 “Once an area has succumbed to dense cheatgrass invasion, there isn’t much you can do,” says Rowland. “People have tried restoration on small scales, but once a threshold is crossed, restoration is nearly impossible without tremendous inputs.” From their landscape assessments in the Great Basin, Wisdom and Rowland estimate that more than 50 percent of existing sagebrush habitat has been invaded by cheatgrass. That’s more than 10 million acres. About 10 percent of that is likely a cheatgrass monoculture. The problem is at its worst at lower elevations. In the colder, moister environments of higher elevations, sagebrush habitat is being assaulted by a wholly different plant

community—and this time it’s native. M. Rowland “Pinyon-juniper woodlands have expanded Once a site has converted to a cheatgrass monoculture it is nearly impossible to restore the native sagebrush ecosystem. throughout the West and have displaced millions of acres of sagebrush habitat,” explains Wisdom. Whereas the problem was “Fire suppression, cattle grazing, and global Often, at moderate elevations, the insult too much fire at low elevations, up high the warming have a combined effect of increasing is twofold. Cheatgrass and pinyon-juniper problem is, in part, owing to the absence of the amount of pinyon-juniper woodlands,” he woodlands encroach together, extirpating fires that once burned every decade or two, says. “And as woodlands expand, sagebrush sagebrush habitat. Eventually intense, keeping woodlands in check. habitat contracts.” cheatgrass-driven fires kill the woodlands too, and exotic grass is all that’s left.

A Sage Icon reater sage grouse are the signature from grouse conservation if it is found in species of sagebrush ecosystems. the same general location. Also, specific G They are the largest grouse in resource requirements must overlap with North America and have beautiful courtship the sage grouse, and management strategies displays every spring. Like the ecosystem must benefit all the targeted species,” says they depend on, sage grouse were once so Rowland. abundant that their current plight would have Wisdom, Rowland and several colleagues been unimaginable. Settlers called them examined the potential conservation cover- “sage chickens,” and ate them alongside age of 39 sagebrush-associated vertebrate domestic poultry. The past notwithstanding, species from sage grouse habitat conserva- sage grouse are in trouble. tion. They mapped the range of habitats for “Their life cycle is tightly linked to the com- all the species to determine spatial overlap position and structure of native sagebrush with sage grouse and evaluated similarity in habitat,” explains Rowland. “When cheat- habitat associations. They also used a cheatgrass enters the system, native understory grass risk model to delineate regions likely to plants are quickly displaced and with them be lost as sagebrush habitat altogether. go the insects. Sage grouse, in turn, are “We found that management for sage grouse deprived of the forbs and protein that are the

Gary Kramer habitat likely would offer relatively high con- primary food sources needed for raising their servation coverage for sagebrush obligates, young. Sagebrush itself is the grouse’s only For many, sage grouse are synonymous with the such as the pygmy rabbit, but far less protec- food source throughout the winter. Without sagebrush ecosystem. tion for other more generalist species, such as healthy sagebrush habitat, there is simply no the lark sparrow,” says Rowland. “Most spe- way to support the sage grouse.” Rowland and Wisdom wanted to know cies of conservation concern in our analyses exactly which species would benefit from this The association between sage grouse and its would benefit only marginally from conser- approach; they wanted to understand whether habitat has prompted land managers to nomi- vation and restoration of sage grouse habi- sage grouse can function as a sufficiently nate sage grouse as an “umbrella species.” tats. About half the species considered had a large umbrella. The idea is: if we protect the sage grouse, neutral response to the umbrella strategy.” we will simultaneously be protecting all the “If the objective is to conserve and restore “Our analyses suggest that the paradigm of lesser known species that also rely on sage- multiple species through the improvement sage grouse as an umbrella for other sagebrush habitat. Protections designed for the of habitats for the umbrella species, several brush species may need to be reevaluated,” grouse, it is hypothesized, could shelter the criteria need to be met. The first, of course, adds Wisdom. entire ecosystem. is co-occurrence. A species will only benefit

3 Restoration Potential he vast area of sagebrush at risk of cheatgrass, and these sites may convert to displacement by cheatgrass and pure cheatgrass in the near future if nothing T pinyon-juniper poses daunting chal- is done,” says Wisdom. lenges for conservation of sagebrush species. “Intensive management practices, including The trick for land managers is determining changes in livestock grazing, are needed which areas to focus their energy on. for sufficient restoration in many areas,” Wisdom and Rowland have pioneered methods he says. “Sagebrush habitats at high risk of for landscape assessment in sagebrush ecosys- displacement by pinyon-juniper woodlands tems that are helping managers prioritize sites require immediate management attention for protection and conservation. According to through the use of prescribed fire or Wisdom, by mapping sagebrush habitats that mechanical treatments to reduce density are highly vulnerable to invasion by cheat- of encroaching woodlands.” grass, versus areas that are highly vulnerable Most areas with high potential to maintain to encroachment by pinyon-juniper woodlands, or restore sagebrush communities are they can provide spatially specific knowledge concentrated in Wyoming, eastern Idaho, needed to target each threat with the appropri- and northern Nevada. Areas with low ate management prescriptions. potential are concentrated in Washington, “Despite declining habitat trends for many parts of Oregon, western Idaho, and much sagebrush species, there is potential to con- of Nevada. serve native sagebrush where large-scale loss Wisdom’s and Rowland’s methods and find- and degradation have not yet occurred, and ings have recently been published as a book, Cheatgrass is predicted to displace existing sage- to restore degraded communities that retain brush and other susceptible land cover types in which has been distributed to federal and native components,” says Rowland. much of Nevada during the next 30 years. Over half private land managers throughout the West. of Nevada is mapped as moderate or high risk area “Understory vegetation communities in high- for displacement. risk areas—usually low elevations and warmer, drier sites—are likely to be dominated by

A glimmer of hope? here is an ecologically driven urgency collaborating on integrated sagebrush research “I listened carefully for to start now,” says Wisdom. “This eco- across the Great Basin. clues whether the West has ‘‘ system is so vulnerable to threshold T “We’ve seen throughout the past decade an accepted cheat as a necessary effects that, once crossed, are nearly impossible to reverse. It is far easier to prevent the upsurge in interest in sagebrush ecosystems. evil, to be lived with until system from reaching thresholds than it is to This trend toward increasing management kingdom come, or whether it budgets and research is exactly what is need- mitigate them after the fact.” regards cheat as a challenge ed. And it must continue,” says Wisdom. “Unlike some other ecosystems, a hands-off to rectify its past errors in approach simply won’t work. Exotic plants, “To further belabor the many ills of the sage- land-use. I found the hopeless brush ecosystem is to ignore the real question altered fire regimes, and historical land attitude almost universal.” use effects all will continue to degrade the of importance: What can be done to improve —Aldo Leopold, A Sand County Almanac, 1949 sagebrush ecosystem if we don’t intervene,” the situation?” says Wisdom. “If we don’t actively manage, then one of the largest ecosystems in North America will disappear.” LAND MANAGEMENT IMPLICATIONS Reversing the trend of habitat loss will take a massive commitment. Indeed, one simula- • Passive restoration, such as changes in management of livestock, coupled with active tion study that Wisdom and Rowland were fire suppression at lower elevations and exotic plant management (e.g., herbicides involved with found that even a six-fold followed by native plant seeding), can be used to restore native grasses and forbs in increase in the areas treated with active the understory of sagebrush habitats within 30 to 50 years. restoration in the interior Columbia Basin would only slow the decline of sagebrush • Sagebrush at high risk of displacement by pinyon-juniper requires immediate habitat, not reverse it. management attention through the use of prescribed fire or mechanical treatments to reduce density of encroaching woodlands. Thankfully, and in part owing to Wisdom’s and Rowland’s research, momentum has • Management of sage grouse habitats is likely to provide substantial conservation been building toward finding solutions in coverage for other species tightly linked to sagebrush, but less coverage for species sagebrush. In fact, a grant of $13 million was with more general habitat requirements. This suggests that the paradigm of sage recently awarded by the Joint Fire Sciences grouse as an umbrella for other, nonobligate sagebrush species may need to be Board to over 20 scientists, representing four reevaluated. federal agencies and six universities, who are

4 FOR FURTHER READING Raphael, M.G.; Wisdom, M.J.; Rowland, M.M.; Holthausen, R.S.; Wales, B.C.; Marcot, B.G.; Rich, T.D. 2001. Status and trends of terrestrial vertebrates in relation to land management in the interior Columbia River basin. Forest Ecology and Management. 153: 63–88. Rowland, M.M; Wisdom, M.J.; Suring, L.H. Meinke, C.W. 2006. Greater sage grouse as an umbrella species for sagebrush- associated vertebrates in the Great Basin. Biological Conservation. 129: 323–335. Wisdom, M.J.; Rowland, M.M.; Suring, L.H., tech. eds. 2005. Habitat threats in the sagebrush ecosystem: methods of regional assessment and applications in the Great Basin. Lawrence, KS: Alliance Communications Group. Several species groups that are associated with sagebrush were evaluated in relationship to their overlap with sage grouse. Species with higher overlap with sage grouse would be better conserved through the Wisdom, M.J.; Rowland, M.M.; Tausch, “umbrella species” approach. R.J. 2005. Effective management strategies for sage-grouse and sagebrush: a question of triage? Transactions, North American Wildlife and Natural Resources Conference. 70: 206–227. Wisdom, M.J.; Rowland, M.M.; Wales, B.C.; Hemstrom, M.A.; Hann, W.J.; Raphael, M.G.; Holthausen, R.S.; Gravenmier, R.A.; Rich, T.D. 2002. Modeled effects of sagebrush-steppe restoration on greater sage grouse in the interior Columbia Basin, USA. Conservation Biology. 16: 1223–1231. Wisdom, M.J.; Holthausen, R.S.; Wales, B.C.; Lee, D.C.; Hargis, C.D.; Saab, V.A.; Hann, W.J.; Rich, T.D.; Rowland, M.M.; Murphy, W.J.; Eames, M.R. 2000. Source habitats for terrestrial vertebrates of focus in the interior Columbia Basin: broad-scale trends and management implications. Gen. Tech. Rep. PNW-GTR-485. Portland, OR: Department of Agriculture, Forest Service, Pacific Northwest Research Station.

These maps show the quality and quantity of greater sage grouse habitat in the interior Columbia Basin for three time points: (1) historical (circa 1850–1890), (2) current (1995), and (3) under proposed management 100 years in the future.

WRITER’S PROFILE Jonathan Thompson is an ecologist and science writer. He lives in Corvallis, Oregon.

5 PRSRT STD US POSTAGE PAID PORTLAND OR FINDINGS PERMIT N0 G-40 U.S. Department of Agriculture Pacific Northwest Research Station 333 SW First Avenue P.O. Box 3890 Portland, OR 97208-3890 Official Business Penalty for Private Use, $300

scientist profiles

MICHAEL WISDOM MARY ROWLAND is Wisdom and Rowland may be contacted at: is a research wildlife a wildlife biologist at Pacific Northwest Research Station/ biologist at Pacific the Pacific Northwest U.S. Forest Service Northwest Research Research Station Forestry and Range Sciences Laboratory Station and is based in and is based in La 1401 Gekeler Lane La Grande, Oregon. Grande, Oregon. She La Grande, OR 97850-3368 Wisdom has been previously worked for Wisdom: (541) 962-6532 involved with large- the Bureau of Land E-mail: [email protected] scale assessments of Management as a sagebrush habitats terrestrial biologist on Rowland: (541) 962-6582 and species in the Western United States the Interior Columbia Basin Ecosystem E-mail: [email protected] since the genesis of the Interior Columbia Management Project. Much of her research Basin Ecosystem Management Project in of the past 5 years has focused on landscape- c o o p e r A t o r s 1994. He also serves as a scientist on the scale analyses of sagebrush habitats and Robin Tausch, Rocky Mountain Research Starkey Project, conducting research on associated wildlife. Her current work Station mule deer, elk, and cattle. He has worked involves evaluation of the pinyon-juniper for the Forest Service and Bureau of Land and cheatgrass risk models developed for Mark Hilliard, Bureau of Land Management Management during the past 25 years on a the Great Basin assessment, and serving as Lowell H. Suring, National Forest System variety of wildlife research topics. project manager and editor of a technical Steve Knick, U.S. Geological Survey, guide for monitoring wildlife habitat on Biological Resources Discipline Forest Service lands. Rick Miller, Oregon State University

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