The Lewis River Hydroelectric Projects - PacifiCorp

Lewis River Interpretive & Education Plan
About half of PacifiCorps’ 10,000 acres of forest land around the reservoirs is
basically left alone—management with a passive approach—allowing the forest
to develop in its own time. But because it would take decades—or perhaps even
longer—for natural succession processes to shape these forests to better support
wildlife (and because, in some cases, the goal is to create even more enhanced
habitat), wildlife managers for PacifiCorp practice “active management” on the
other half. Active management involves many techniques of modern forestry,
including:
Thinning
Thinning takes out some of the trees in a stand, allowing more light through the
canopy to the forest floor. This promotes strong understory growth, essential
for forage and cover. Several different styles of thinning are used on PacifiCorp
lands, including traditional thinning where individual trees are selectively
logged from older forests; pre-commercial thinning (where competing conifer
seedlings are removed from young forest stands), pruning, where lower branches
are removed just when young trees begin to close up ranks in a planted area,
which extends the time that sun-favoring forage plants can grow underneath
and between them; and selectively killing (herbicide) young trees just at the
crown-closure stage.
Clearcuts
Clearcuts provide larger areas of well-lit, clear ground for early-successional
plants to grow. Many of these plants are important forage species for deer and
elk; they may also be important for some birds and small mammals. Small
clearcuts (10 acres or less) are commonly used on PacifiCorp lands to provide
these openings. (Clearcuts are also used where a section of forest has become
infested with a disease such as root rot). Usually, some of the overstory trees are
left standing. After the area is cut, it is planted with grass seed in the fall, and
then in spring it is replanted with conifer seedlings (usually Douglas-fir, but
sometimes western red cedar, hemlock, or ponderosa pine).
From an elk or deer’s perspective, for the first 2-10 years the clearcut is a source
of forage: grass and new early-successional growth. After 10-12 years the earlysuccessional
plants become less common and the area becomes more important
for bedding and cover, while still providing forage on about 50% of the area.
Habitat management on PacifiCorp lands seeks to maintain a patchwork of
lands in various stages of development, a kind of mosaic in space and time, for
diversity.
Snag Creation
One of the most visibly successful programs in terms of bird habitat is snag
creation, in which live trees are topped and limbed, and the tops prepared so as
to make them suitable for nest platforms. Snags are very important habitat for a
Sea Reach Ltd • 146 NE yamhill Street • Sheridan, OR draft 3 • November 2008 • page 79