Sagebrush steppe, aspen, and mountain shrub communities are three of the five key priority habitats in the WLCI area.
Sagebrush (Artemisia spp.) communities have been identified as one of the most threatened communities in western North America. Many sagebrush locations have been identified as being in poor health with old and unproductive plants with few understory herbaceous plants. However, because of the need to protect sage-grouse and other sagebrush obligate species, habitat treatments are limited to those areas where maintenance or restoration of sagebrush stands is needed the most. This includes areas within sage- grouse core and non-core areas threatened by invasive plant species or conservation actions associated with crucial winter and transitional ranges that overlap with sagebrush systems. There are a few proposed projects that are directly targeted to benefit sage-grouse through direct manipulation of sagebrush stands. These are designed to increase herbaceous plant species, diversify sagebrush age and stand structure, and increase suitable habitat for different life stage needs (for example increasing the abundance of small insects in early brood-rearing habitat). In general, maintenance and protective activities were identified by LPDTs as the preferred approach especially where there are large intact sagebrush patches or sagebrush areas that are associated with sage-grouse or other sagebrush obligates. Enhancement and restoration projects are being implemented in areas where more aggressive actions are needed to prevent additional loss of sagebrush from invasive plants, or where junipers (Jupinerus spp.) and other conifer species have encroached into sagebrush areas. One of the highest priorities related to sage-grouse and suitable sagebrush communities are to protect these areas from invasive plant species and additional disturbance activities. Placing markers on new or converted fences continues to be a priority by LPDTs to protect sage-grouse. Placing markers on fencing is a very inexpensive way to reduce sage-grouse mortality. In addition, LPDTs will continue to work with land management agencies to identify areas in both sage-grouse core areas and non-core areas to treat invasive plant species.
Any projects in sagebrush communities follow best management practices for sage-grouse and other sagebrush obligates as identified by state and federal agencies. Projects in sage-grouse core areas are required to follow the Wyoming sage-grouse core area rules and guidelines with regard to leks and disturbance benchmarks. WLCI’s efforts to maintain, enhance, and restore sagebrush at landscape scales are designed to meet objectives and actions identified in the USFWS’s Greater Sage-grouse Conservation Objectives: Final Report (U. S. Fish and Wildlife Service, 2013).
Where suitable, treatment priorities are being designed to:
- maintain or enhance natural patterns (e.g. seasonal migrations), functions (e.g. cover/food), and processes (e.g. fire) in stable productive sagebrush systems;
- inter-seed sagebrush stands with forbs and grasses using native seed where appropriate;
- establish habitat leases with willing landowners to maintain habitat intactness and preserve sagebrush habitat;
- develop grass banks or forage reserves to provide management opportunities for sensitive big sagebrush communities (this may include, but is not limited to, assisting livestock operators with moving grazing to other areas during habitat improvement projects and rest periods);
- thin dense, over mature sagebrush to meet sage-grouse requirements;
- create mosaic patterns with diverse sagebrush densities and age structure;
- regenerate and restore sagebrush and increase grass and forb diversity;
- eradicate, reduce, or control of invasive plant species especially in areas crucial to important life stages;
- use fence markers to reduce sage-grouse mortality;
- reduce junipers that have encroached into sagebrush areas;
- protect springs and seeps within the sagebrush system;
- and, improve resistance and resiliency to invasive plants and prolonged droughts.
There are several sagebrush obligate species that will benefit from WLCI sagebrush habitat projects. Some of these species include the sage-grouse, burrowing owl (Athene cunicularia), pygmy rabbit (Brachylagus idahoensis), brewer's sparrow (Spizella breweri), and sage thrasher (Oreoscoptes montanus). These actions also benefit large and small predators, raptors, and large ungulates moving seasonally through these habitats.
Aspen stands are hotspots of biodiversity, providing shelter and forage for elk, moose and mule deer, stopover habitat for dozens of species of migrating songbirds during spring and fall, and providing cool, moist microclimates that support amphibians, reptiles, and many invertebrates, such as snails. Aspen in the WLCI area are susceptible to sudden aspen decline and other mortality events. Common issues associated with aspen communities include limited stand and age structure, insect and fungal disease, excessive herbivory, low regeneration, fragmentation, and competition with conifer species. WLCI has funded numerous aspen projects, many of which are planned to continue for 10 to 20 years. Aspen treatment objectives are designed to:
- increase the health, vigor, and resilience of important aspen communities to withstand transforming events such as sudden aspen decline, disease, and prolonged droughts and climate change;
- increase regeneration rates of aspen and to create diverse age structures;
- reconnect aspen stands where appropriate to reduce fragmentation;
- restore high priority aspen stands to support resident and migratory songbirds;
- improve water quality and quantity of headwater streams;
- moderate steam temperatures to support important fisheries;
- serve as a food source and building material to support viable beaver populations;
- reduce conifer encroachment and increase biodiversity;
- and, moderate excessive herbivory where appropriate.
Mountain shrub communities are transitional areas that lie between sagebrush habitats and conifer forest habitat at higher elevations. Mountain shrub provides parturition cover for mule deer and other large ungulates cover and forage during ungulate seasonal migrations, and early winter browse for these same animals. In addition, mountain shrub habitats support unique bird and small mammal assemblages. Like aspen, mountain shrub habitats are also susceptible to climate changes, energy development, heavy browsing by ungulates, and altered fire regimens. WLCI partners are working in all three of these habitat types to improve vegetative health and reduce stresses, better-enabling these plant communities to be resilient to impacts from fire, invasive plant species, heavy browsing, and drought conditions.
Mountain shrub communities are one of the more difficult plant communities to characterize in the WLCI area. Mountain shrubs can be associated in large dense patches to small isolated patches dominated by mountain sagebrush and other species. Mountain shrubs are typically located on hill slopes at low to high elevations as a dominant patch or as understory species in woodland settings. As a WLCI focal community, mountain shrubs generally include saskatoon serviceberry (Amelanchier alnifolia), true mountain mahogany (Cercocarpus montanus), curl-leaf mountain mahogany (Cercocarpus ledifolius), chokecherry (Prunus virginiana), antelope bitterbrush (Purshia tridentata), sumac (Rhus trilobata), currant and gooseberries (Ribes spp.), and similar species. These species are not treated as a mountain shrub focal community when they are an understory component in aspen and other woodland communities. Mountain shrub communities are important to many game and non-game species.
Like aspen communities, mountain shrub communities in the WLCI area share many of the same issues and conservation needs. Issues include the lack of recruitment and regeneration, excessive herbivory, reduced age structure, invasive plant species, and encroachment of juniper. Mountain shrub communities are not typically well mapped and information about their age, stand structure, and condition is lacking in many areas. Data associated with the WGFD long-term monitoring of mountain shrub communities indicate that mountain shrubs have very little annual net leader growth and recruitment in areas associated with heavy browsing. There is also concern that mountain shrub communities that are located within or near crucial habitats are more severely impacted especially where energy development is occurring. LPDTs suggested giving mountain shrub communities within crucial winter habitats, transitional areas, within or near big game parturition areas, and areas adjacent to or within energy development. Some of the more specific locations within these areas reflect locations identified by the 2009 Wyoming Range Mule Deer Assessment and data and expertise by WGFD and BLM resource specialists.
LPDTs have identified treatment priorities to:
- maintain and protect functional mountain shrub communities and ensure connectivity between stands and seasonal habitats are maintained;
- facilitate ability of certain shrubs (e.g. chokecherry, mountain mahogany, serviceberry) to grow above browse heights;
- improve age and stand structure;
- restore mountain shrub diversity and abundance;
- reduce impacts from excessive herbivory and browsing; and
- remove juniper trees that are expanding and outcompeting deciduous mountain shrub species.
Treatment tools include prescribed fires, mechanical treatments, and fencing. More unique approaches identified include the use of fencing to increase snow accumulation for moisture and planting of shrubs to disperse ungulates and reduce browsing at stands that are being compromised. Ongoing and proposed treatments will support objectives related to the state mule deer initiative and Wyoming Range Mule Deer Plan.