||Sagebrush ecosystems represent one of the largest potential vegetation types in the
western United States and function with incredible ecological influence across the
landscape. Intimately connected to and dependent on functioning sagebrush habitat,
the Greater sage-grouse (Centrocercus urophasianus) has been significantly impacted
by widespread loss, fragmentation, and alteration of sagebrush- their current range
is only 56% of historical distribution.
Habitat impacts imposed by conifer encroachment and altered fire regimes present some
of the most significant threats to sagebrush and sage-grouse habitat. Historically,
fire was the dominant disturbance force shaping western sagebrush systems. However,
post settlement impacts of livestock grazing, fire suppression and influx of invasive
species have altered fire regimes contributing to disturbance events that function
outside of the historical range of variability. Changing dynamics have facilitated
the encroachment of conifers into historically shrub dominated sagebrush ecosystems.
Increased woody fuel loads feed fires that burn more frequently and with greater intensity-
severely impacting sagebrush and sage-grouse habitat.
Threat to sagebrush ecosystems and decline of species like the sage-grouse has led
to interest in habitat restoration. Because 64% of sagebrush habitat is federally
managed, agencies like the U.S. Fish and Wildlife Service play a leading role in the
science behind and implementation of restoration projects. For the 1.1 million acre
Charles M. Russell (CMR) National Wildlife Refuge in central Montana, management of
sage-grouse habitat has been identified as a priority for current and future action
planning. For many federal managers tasked with planning sage-grouse habitat treatment
projects, lack of data is a limiting factor and there is a great need for further
Research objectives were to investigate the relationship between habitat characteristics,
fire history and sage-grouse on CMR in order to develop data and models for planning
fuels treatment projects that address conifer encroachment within the context of federal
land management. Addressing local scale fire-habitat dynamics provides data to help
managers balance cost efficiency and resource benefit when choosing between mechanical
thinning and prescribed burning.
Habitat variables including conifer cover, sagebrush cover and fire history were quantified
through spatial data mapping and then statistically analyzed in generalized linear
models. Fire history was found to have a significant impact on lek attendance (for
every 1% of the lek area burned, attendance was reduced by 6.5% and 7.5% for females
and males, respectively). Composition of sagebrush and conifer cover was quantified
for 18 active leks and treatment priorities were recommended.
Treatment Prioritization- Target Lek Criteria
1. sagebrush cover between 25% and 65%
2. conifer cover >4% within 2km