» Understanding Habitat Needs
Sagebrush
and Sage-grouse
Photo by Michael Wisdom
For decades, greater sage-grouse populations have been in dramatic
decline across their North American range in response to the
harmful effects of various human activities and land uses. To
better understand the impacts of land use and habitat changes
on sage-grouse, research wildlife biologist Michael Wisdom and
colleagues used novel landscape modeling methods to conduct a
comprehensive, rangewide analysis. The study considered 22 environmental
factors in areas currently inhabited by sage-grouse compared
to areas where the species is locally extinct. The researchers
identified threshold values for the amount of sagebrush critical
to sage-grouse persistence—addressing a key question about
the species’habitat requirements—and also revealed
the potentially negative impacts of communication towers and
power lines on the species’occurrence.
For more information: Sage-Grouse
on the Edge: Understanding and Managing Western Landscapes for
Their Survival, Science Findings 142: http://www.treesearch.fs.fed.us/pubs/40561.
Contact: Michael
Wisdom, mwisdom@fs.fed.us
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Where the Snow
May Go
Photo by Cathy Raley
Wolverines live in areas that support persistent snow cover
through mid May. Even in summer when the snow has melted, wolverines
stay within these bioclimatic envelopes. Their habitat needs
make the species especially vulnerable to climate-induced changes
in snow timing and duration.
Research wildlife biologist Keith Aubry and colleagues modeled
the distribution of snow cover within the Columbia, Upper Missouri,
and Upper Colorado River Basins to identify likely impacts of
a changing climate in these three basins under several global
climate modes. The researchers estimated snow cover using a hydrologic
model based on patterns in temperature and precipitation. Their
modeling revealed that roughly two-thirds (67%) of predicted
spring snow cover will persist within the study area through
2030 and 2059, and just over one-third (37%) will persist through
2070 and 2099. Maps based on this output identify areas where
losses in snow cover might be greatest and which areas would
retain snow cover throughout the 21st century. This information
can help wildlife managers anticipate and plan for habitat isolation.
For more information: Climate
Change Predicted to Shift Wolverine Distributions, Connectivity,
and Dispersal Corridors: http://www.treesearch.fs.fed.us/pubs/40192.
Contact: Keith Aubry, kaubry@fs.fed.us
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Seasonal
Habitat Changes
Photo by Rhonda Mazza
As instream conditions change throughout the year, juvenile
coastal cutthroat trout, steelhead, and coho salmon move to different
parts of the steam. Along with water levels, these movements
are likely triggered by changing needs as the young fish grow
and by inter- and intraspecies competition. Side channels and
valley floor tributaries (5% of the available habitat), for example,
contained 20% to 60% of the total coho salmon fry in the basin
in the spring. Abundance in these areas declined as streamflow
decreased from June to August in this coastal Oregon stream.
Pools, generally created by the presence of large woody debris,
were very important for older juvenile salmonids. Research fish
biologist Gordon Reeves and colleagues also found that cutthroat
trout congregated in the uppermost reaches, steelhead occupied
the lowest reaches, and coho salmon inhabited the middle reaches.
This study demonstrates that basinwide distribution of salmonids
varies among species, age classes, seasons, and years. This information
can help fish managers responsible for developing management
options and evaluating likely impacts of proposed actions on
salmon habitat.
For more information: Seasonal
Changes in Habitat Availability and the Distribution and Abundance
of Salmonids Along a Stream Gradient from Headwaters to Mouth
in Coastal Oregon: http://www.treesearch.fs.fed.us/pubs/39966.
Contact: Gordon Reeves, greeves@fs.fed.us
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A
Focus on Forage
Photo by Alaska Department of Fish and Game
The Forage Resource Evaluation System for Habitat is a tool
to quantitatively evaluate the quantity and quality of available
food resources for deer. Research wildlife biologist Tom Hanley
and colleagues developed the system to help wildlife biologists
and resource managers compare different parts of a landscape
at different times and under different conditions based on their
suitability to support Sitka black-tailed deer in southeast Alaska.
Users input the available biomass and nutritional quality of
a habitat’s food resources and the metabolic requirements
of deer, which vary depending on season and reproductive status.
The model then generates a variety of outputs, including the
number of days the landscape’s food resources can support
deer. Although the tool was developed for black-tailed deer in
Alaska, it also can be applied to other species of deer elsewhere
in the world.
For more information: http://cervid.uaa.alaska.edu/deer/home.aspx
Contact: Tom Hanley, thanley@fs.fed.us
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Featured Scientist
 Sherri
Johnson is a research ecologist with the station’s
Ecological Process and Function program. She also is the lead scientist
at the H.J. Andrews
Experimental Forest. Her research examines the complex interactions
between forests and streams so that potential impacts can be better
understood. Johnson and her colleagues have been analyzing long-term
stream flow and stream chemistry data to evaluate trends over time
in nitrogen dynamics from 23 undisturbed watershed across 11 experimental
forests. In a different project, she has been studying uptake processes
of nitrogen in streams. Nitrogen is a critical nutrient for all organisms,
and Johnson found that half of one form—ammonium—was
taken up over short travel distances in the stream, with the rest
being converted to another form and transported downstream. Johnson’s
research has also revealed that forest type is not a good predictor
of concentrations of in-stream nitrogen. Johnson can be reached at sherrijohnson@fs.fed.us and
(541) 758-7771.
Tools and Software
Habitat Connectivity
 Habitat
connectivity is a major focus of conservation biology. Fragmented landscapes
can reduce gene flow and genetic diversity in wildlife populations,
putting species at greater risk for extinction. A new framework helps
managers and wildlife planners design wildlife corridors that improve
connectivity in fragmented landscapes. The framework uses expert opinion
as a starting point and then either validates its assumptions or identifies
a peak of support for a new model more highly related to genetic isolation.
Recently, the framework was used to study a population of mountain
goats in a fragmented landscape in the Cascade Range. It is also being
used by the Washington Department of Transportation to assess landscape
connectivity along the I-90 corridor.
For more information: http://waconnected.org
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