Foothill Shrublands Photo courtesy of Jerry Altermatt, WGFD Table of Contents Habitat Description .......................................................................................................................... 2 Foothill Shrublands Wildlife ............................................................................................................. 5 Current Foothill Shrublands Conservation Initiatives ..................................................................... 11 Recommended Foothill Shrublands Conservation Actions ............................................................. 12 Foothill Shrublands Monitoring Activities ...................................................................................... 13 Literature Cited .............................................................................................................................. 14 Wyoming State Wildlife Action Plan - 2017 Page III – 4 - 1 Habitat Section Wyoming Game and Fish Department Foothill Shrublands Habitat Description habitats in southern and western Wyoming at elevations from 5,000 to 9,000 feet (Harrington The foothill shrublands habitat type, commonly 1954). It is primarily found on dry ridges and known as mixed mountain shrubs, comprises slopes in association with big sagebrush, piñon diverse plant communities dominated by an pine, juniper, and aspen. Antelope bitterbrush equally diverse list of shrub species. is found in many of the same locations as NatureServe (2010) estimates over 4.1 million serviceberry, including central Wyoming, but is acres of foothills shrublands systems in often more confined to areas where snow Wyoming when the Inter-Mountain Basins accumulates, such as ravines, or in areas with Montane Sagebrush Steppe system is included. higher precipitation. Snowberry is found along Typically found in patches of pure or mixed stream banks in Wyoming, in swampy thickets, stands, predominant shrub species include true moist clearings, and open forests at elevations mountain-mahogany, curl-leaf mountain- from about 4,600 to 9,200 feet. mahogany, serviceberry, antelope bitterbrush, The quality and composition, including skunkbush sumac, currant, gooseberry, and dominant species, of foothill shrublands have snowberry. Mountain big sagebrush and silver varied since European settlement (Nicholoff sagebrush are also common. Choke cherry may 2003). Many stands have declined through a also be present, sometimes in abundance in combination of fire suppression and moist sites. Associated grasses and forbs overbrowsing. Fire is a naturally occurring include arrow-leaf balsam-root, bluebunch process in lower montane and foothill wheatgrass, hairy golden-aster, Junegrass, and shrublands. Native fire regimes in these lupine (Knight 1994). communities probably vary widely with local Two types of mountain-mahogany commonly site factors. Severe, high-intensity fires are occur in Wyoming. True mountain-mahogany, probably rare under natural conditions due to a deciduous species, is found in the Black Hills low and patchy fuel loads and relatively high site and across the southern half of the state, while moisture (Decker 2007). Historically, foothill curl-leaf mountain-mahogany, an evergreen shrublands likely burned every 50 to >100 years species, is in the foothills of the Bighorn (J. Derner personal communication 2010). In Mountains and to the west and south (Knight the absence of fire, foothill shrublands are often 1994). These shrubs form dense thickets on invaded by juniper and pine, and also increase in rocky or shallow soils from the western Great shrub density. Both changes can increase fire Plains up to an elevation of 7,800 feet. Both intensity and hinder post-fire recovery time. species have the ability to fix nitrogen, which The ability of true mountain-mahogany to improves soil fertility over time (Hoeppel and resprout from the crown allows it to recover Wollum 1971, Lepper and Fleschner 1977). relatively quickly from fires. Alternatively, curl- Mountain-mahogany also plays an important leaf mountain-mahogany only regenerates from role in erosion control because the shrubs are seed, which can result in extremely long fire long-lived, produce extensive root systems, and recovery times (Kitchen 2008). Fire survive well on dry steep slopes. Additional suppression is believed to be contributing to information on these two species has been curl-leaf mountain-mahogany encroachment compiled by Blauer et al. (1975); some is into adjacent communities (Arno and Wilson available on the Nature Serve (2010) web site, 1986); however, over time, some stands become within the summary for the Inter-Mountain decadent and are unable to compete with Basin Curl-leaf Woodland and Shrubland conifers (Nicholoff 2003). A similar trend of ecological system. expansion has occurred within antelope Saskatoon serviceberry is a common foothills bitterbrush in ponderosa pine communities. shrub, but is scattered throughout the state. Likewise, serviceberry and skunkbush sumac Utah serviceberry is found in drier foothill Wyoming State Wildlife Action Plan – 2017 Page III – 4 - 2 Habitat Section Wyoming Game and Fish Department Foothill Shrublands have declined with increasing shade from higher densities of mature trees (Nicholoff 2003). Foothills receive considerable recreational activity, especially in the warmer seasons, including hiking, camping, hunting, and motorized vehicle use. Some locations are also popular for housing. Livestock grazing is common. Limited oil and gas development occurs in foothill shrublands, but wind energy development is increasing. Wyoming State Wildlife Action Plan – 2017 Page III – 4 - 3 Habitat Section Wyoming Game and Fish Department Foothill Shrublands FIGURE 7. Wyoming Foothill Shrublands TABLE 7. Wyoming Foothill Shrublands NatureServe Ecological Systems1 1. Harvested forest-shrub regeneration 2. Inter-Mountain Basins Mountain-Mahogany Woodland and Shrubland 3. Northern Rocky Mountain Montane-Foothill Deciduous Shrubland 4. Rocky Mountain Lower Montane-Foothill Shrubland 5. Western Great Plains Wooded Draw and Ravine 6. Inter-Mountain Basins Montane Sagebrush Steppe 1 Descriptions of NatureServe Ecological Systems which make up this habitat type can be found at: NatureServe Explorer: an online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. http://www.natureserve.org/explorer. Wyoming State Wildlife Action Plan – 2017 Page III – 4 - 4 Habitat Section Wyoming Game and Fish Department Foothill Shrublands TABLE 8. Wyoming Foothill Shrublands increase cover and forage for wildlife. Frequent Species of Greatest Conservation Need rock outcrops can serve as important substrates for bats, bighorn sheep, bushy-tailed woodrats, Mammals and other species. Foothill shrublands often Bighorn Sheep occupy rough topography which provides cover Dwarf Shrew for various wildlife, and also a high diversity of Eastern Spotted Skunk micro-climates, which in turn increases plant Hispid Pocket Mouse diversity. Many of these communities have Idaho Pocket Gopher Olive-backed Pocket Mouse been designated as crucial winter ranges for Silky Pocket Mouse mule deer, elk, moose, and bighorn sheep. Yuma Myotis Foothill shrublands provide habitats for bird species including Columbian sharp-tailed Birds Bewick’s Wren grouse, dusky (blue) grouse, Brewer’s sparrow, Black-throated Gray Warbler gray flycatcher, dusky flycatcher, green-tailed Ble-gray Gnatcatcher towhee, common poorwill, Virginia’s warbler, Brewer’s Sparrow black-throated gray warbler, and Lazuli bunting Calliope Hummingbird (Nicholoff 2003). Presence of substantial Canyon Wren amounts of sagebrush, typically mountain big Columbian Sharp-tailed Grouse sagebrush, promotes occupation by several Greater Sage-Grouse Loggerhead Shrike sagebrush obligate wildlife species including Sagebrush Sparrow sage-grouse, sage sparrow, and sage thrasher. In Sage Thrasher fact, in some seasons and conditions, like late summer and during droughts, the wetter foothill Reptiles shrub communities may provide better habitat Smooth Greensnake for sage-grouse than lower and drier Pale Milksnake communities of pure big sagebrush. Rubber Boa Valley Gartersnake Foothill shrublands provide particularly important habitat for big game in winter and Amphibians during seasonal migrations. Both species of Northern Leopard Frog mahogany are particularly favored by mule deer Columbia Spotted Frog for browsing. Curl-leaf mountain-mahogany communities provide important wintering Foothill Shrublands Wildlife habitat for mule deer, elk, and bighorn sheep in Wyoming (Despain 1973, Olson 1992, The mid-elevation position of foothill Kauffman et al. 2009). It tends to grow on dry, shrublands denotes a rather mesic environment steep slopes that are typically more accessible to which is not as cold and snowy as mountains, big game and other wildlife during deep snow but not as dry and hot as basins. Thus, this conditions. Curl-leaf mountain-mahogany habitat type is often more productive than the maintains high levels of crude protein (Welch forests above it and the shrublands below it. It 1981) and is one of the few shrubs that meet big supports many berry-producing shrubs such as game protein requirements throughout winter. snowberry, currant, serviceberry, choke cherry, Antelope bitterbrush is another high-quality and Oregon-grape, which are important forage preferred forage for both big game and for many mammals, such as black bears and livestock, especially in fall and early winter