OES Ecological Restoration Update
January 2014
Hi all!
I have had a lot of questions
from teachers and students at OES about the work that Clean Water Services is
doing in the marsh and forest on school property. I am going to try using this online forum to
provide the update information to everyone.
Let me know what you think.
CWS Background:
Clean Water Services is the
wastewater and stormwater management utility in the Tualatin River
Watershed. Clean Water Services operates four
wastewater treatment plants and 40 pump stations. We also work with our 12
member cities to build and maintain the public sanitary sewer and surface water
management system. The Watershed
Management Department (where I work) does ecological restoration projects
throughout the basin. Often working with
city, nonprofit and school partners, we improve water quality by building and
improving plant communities along waterways.
We tend to focus our projects on establishing plants along streams to
shade the water (which prevents the water from becoming too warm to support our
fish populations) and creating wetland complexes that retain stormwater and provide
wildlife habitat.
Vegetation Restoration Projects in General:
These projects involve weed removal, replanting,
monitoring and maintenance. The trees
and vegetation being removed are nonnative invasive species. That means
they are both species that were introduced to the local ecosystem and also that
they tend to grow aggressively and outcompete native species. That is
ecologically harmful because you wind up with monocultures (dense stands of a
single species) rather than a mix of native trees and shrubs with room for
younger age classes of trees to root and grow. It is harmful from a
stormwater management perspective as well since many of the invasive species
(especially the ones that grow as groundcover) out-compete shrubs with deeper
root systems that prevent erosion. Invasive grasses form dense
monocultures that lack the habitat value of diverse wetland grass assemblages
but still don’t provide the shade that shrubs would.
The species we are removing are English
ivy, English hawthorn, Himalayan blackberry, pie cherry, English holly, reed
canary grass, Portuguese laurel and others. When this involves spraying
herbicide we only work while students are not on campus and our contractors post
signs with the name of the chemicals being used. The spray itself is mixed with blue dye to
make it clear where work is happening. Once the spray is dry it is safe
to walk through the area but the blue dye will be visible for a while
afterwards.
We will also be doing cut work that
involves chain saws or brush cutters. When
our crews are sawing they will either be dropping invasive trees and shrubs,
girdling invasive trees (which kills them but leaves them standing) or cutting
around plantings to decrease competition. Stumps with blue dye are from weed
trees like hawthorn that were cut and sprayed to prevent them from resprouting.
We will be replanting with native trees
like oak, ash, maple, western redcedar, and cascara; shrubs like willow,
spirea, dogwood, twinberry, snowberry, red-flowering currant and ninebark; and
wetland sedges and rushes.
Schedule:
Fall
2013- Himalayan blackberry, teasel, yellow flag iris removal
December
2013- English hawthorn, invasive
cherry and holly removal and chipping (the pile of chipped material is fair
game if anyone wants to spread it on trails or around the planting down by
SPARC).
January
2014- Ground ivy spray and cutting climbing ivy at the base of trees
February
2014- Planting around the edges of the ponds in the middle of the site. We
will focus on the areas where there are fewer remaining invasive plant species.
Spring
and Summer 2014 – Continued invasive species removal (teasel,
blackberry, ivy and hawthorn especially)
Winter
2014-15- larger scale planting throughout the site as part of our 1 Million, 1
Year, 1 Water campaign.
**And ongoing after that, we are
required to maintain this site for at least the next 10 years.
Map:
How students can be involved:
The triangular area south of Vermont and
east of Nicol will be available for planting by classes that would like to help
out next fall or during the spring of 2015.
Teachers who would be interested in
attending a turtle monitoring training and doing surveys on the ponds should let
me know.
Any class or student can walk around,
make observations on plants and animals, take pictures, sample water quality or
map invasive species populations over time.
I hope you all appreciate how special it
is to have a backyard like the one OES has!
Thanks!
Margaret Wagner
Clean Water Services
