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Question answered: Why do the plants on
the new
Kootenai River Islands look so brown? |
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May 30, 2016 |
Here at NewsBF, we've had people ask why the new
plants placed on the newly-constructed islands
just last fall already appear to be brown and
dead. We put that question to the staff at the
Kootenai Tribe's Fish and Wildlife Department.
Following is their answer to our question.
by the Fish and Wildlife Department
Kootenai Tribe of Idaho
Why do the plants on the newly constructed
islands in front of the Kootenai River Inn look
like they are already dead? The answer is that
the new plantings aren’t dead at all, but they
are hiding behind bundles of dead branches and
brush. What you’re seeing is new way of
protecting the plantings on the islands from
being eaten by our Bonners Ferry area wildlife.
Last summer the Kootenai Tribe of Idaho
constructed the first half of a two-year project
to help endangered Kootenai River white
sturgeon, burbot and other native fish. The
Bonners Ferry Islands project includes
excavation of pools, construction of structures
to protect the river bank and provide fish
habitat, bank restoration, construction of two
islands and revegetation of the islands and
river banks.
The 2015 vegetation work included planting
seeds, native trees, shrubs, and live willow
cuttings on the islands and north river bank
across from the Kootenai River Inn. Once these
plants take hold they will help to stabilize the
islands and river banks. The plants also play an
important role in helping sturgeon, burbot and
other fish by improving the food web in the
river. When insects and debris from the plants
drop into the river they help provide nutrients
and food for fish.
So, back to those brown dead plants on the
islands. The Kootenai Tribe is trying out a new
way to protect the freshly planted vegetation
from being eaten by deer, beaver, geese and
other wildlife. Last summer the Tribe’s
contractors wrapped the new plantings in bundles
of already dead branches and brush to protect
them from browsing by wildlife while the plants
get big enough to survive on their own
These protective brush bundles were designed to
create conditions similar to what you would find
on a natural, densely vegetated island or
riparian area.
Because the newly-constructed islands were
completely bare when it was time to put plants
on them, the bundles were needed to give the new
plantings some protection. The brown, dead
plants we are seeing on the islands and river
bank are not the new vegetation planted on the
islands—they are the outer bundles of protective
brush.
Many of the branches used to make these
protective bundles came from conifer trees that
had green needles when they were put in place.
While the needles of those branches stayed green
through most of the winter, they have now turned
brown. The conifer needles will drop to the
ground soon helping to build new soil on the
islands.
The new living trees and shrubs are growing
within the protected areas created by the bare
limbs and brown branches of the protective
bundles.
These plants will continue to grow and mature,
and should fill in the spaces between the brush
bundles and over time grow taller than the
brush. Eventually the brush will decompose
leaving just the living plants.
If you look closely now, you’ll see the green
leaves of the planted native trees and shrubs
are beginning to show through the brush. More
and more green will become visible on the
islands as summer comes and the river flows
subside.
Now that the Kootenai River stage is high,
plants on the islands are partly under water.
Fortunately, these plants are native riparian
species and they are adapted to being under
water or partially submerged for several days or
even weeks during the growing season.
Some of the willow species, such as sandbar
willow, are planted at lower elevations on the
islands and these willows commonly survive up to
six weeks under water during spring and early
summer. Other shrubs such as alder and dogwood
were planted slightly higher, but these plants
can also survive days or weeks under water.
Plants like chokecherry and rose are less
tolerant of being submerged for long periods and
these were concentrated on the highest parts of
the islands. The current high water is giving
last year's planting a much-needed watering, and
once the water recedes, green leaves and new
growth will be visible as the new vegetation
starts to establish on the islands.
The Kootenai Tribe’s contractors will be out
monitoring the vegetation this summer to see how
well this approach is working and make
adjustments if needed.
The Tribe will begin construction of the second
part of the Bonners Ferry Islands project later
this summer. Stay tuned for more news about this
project.
The Bonners Ferry Islands project is part of a
larger Kootenai Tribe of Idaho program, the
Kootenai River Habitat Restoration Program,
which is funded by the Bonneville Power
Administration.
Additional information and progress updates are
available on the Kootenai Tribe’s website:
www.restoringthekootenai.org.
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