union bay natural area restoration strategy
TRANSCRIPT
Introduction
The Union Bay Natural Area (UBNA) is a 73.5-acre public wildlife area and natural restoration
laboratory composed of grasslands, modest ponds, and lake shoreline that is a sanctuary for over
200 species of birds including crested cormorants, great blue herons, and eagles. Considered
Lake Washington’s second largest ‘natural’ ecosystem and one of Seattle’s largest public green
spaces (Howell et al. 2009), UBNA It is located at the east end of the University of
Washington’s campus, south of NE 45th Street and west of Laurelhurst. Currently, UBNA is
managed by the University of Washington Botanic Gardens.
History of Union Bay Natural Area
In 1916, the United States Army Corps of Engineers lowered Lake Washington to match the
water levels of Lake Union and the Puget Sound for navigation and commerce, creating a marshy
area. This marshy area was used by the City of Seattle from 1925 to 1966 as landfill (Howell et
al. 2009). When the City closed the landfill in 1966, it was capped with a thin layer of soil and
clay from a nearby construction site. In 1971, the University of Washington gained ownership of
the marsh and designated it as a Natural Area.
Description of Site
Our site was lumpy with two muddy and wet areas, was relatively bare and open, and surrounded
by grasses, patches of blackberries, and a treeline in the distance. The only vegetation was small
blackberry plants that had survived tilling and herbicide. There was little plant diversity or
vegetation that remained after we planted our own species. The soil itself appears to have a high
clay content, with poor drainage leaving pools of water on the surface of the plot in low spots. In
the winter in the PNW, the climate is wet and mild (Mediterranean climate) so there are many
overcast days that contributed to the wet soil.
Human Impacts and Disturbances
Restoration Objectives
Overall goal: Remove invasive species and reintroduce natives in order to restore the prairie area
south of Shoveler’s Pond.
● Objective 1: Removal of invasive species for the prevention of reestablishment
● Objective 2: Plot preparation for the reintroduction of native plants
● Objective 3: Plant native grassland species that will reestablish the prairie ecosystem and
suppress potential invasive species
Treatments Performed
Our team first created a plan to plant the plugs of grasses that we were given. We decided to
plant one Festuca idahoensis individual on the top of each mound, as they are adapted to
exposed, dry sites. We also placed the Festuca in some of the flat, stable areas of our site away
from the water. Because we had quite a few Deschampsia cespitosa individuals, we decided to
evenly distribute them around our plot (5 per mound, and dispersed along the rest of the site). As
those who did not survive would not be detrimental losses and we did not want to crowd the
better regions of our site. We also hoped that some would survive in the moist area, because we
were not going to risk our other species in the unfavorable conditions. The Danthonia californica
species were much smaller and more delicate than expected and came in around 7 individuals per
pot. We placed them on the slopes of the mounds because they prefer dry soils, and along the top
right corner of our site. The Elymus glaucus species were placed along the base of the mounds
and near the edge of the moist soil, as they are able to tolerate wet areas and enjoy stream edge
areas.
Next, our team decided where to plant the seeds. After stratifying in near-boiling water the night
before, the Lupinus Latifolius seeds were ready to be planted. These seeds are fairly viable, and
there were 100 seeds per packet (200 seeds total). Because lupines can tolerate a range of soils
and because we had an abundance of seeds, we planted each seed somewhat evenly around the
site except for the more moist area out of concern that they would not sprout submerged in water.
Our team shared a packet of Carex pachystachya with another group, and we received 0.25 oz,
which was still plenty of small yellow seeds. These are also good wetland colonizers, so we
planted these seeds about the entire site but more heavily around the moist area. We attempted
two planting techniques: placing into slightly depressed soil and covering lightly (on the mounds
and dryer soils), and wind scattering with the leftover seeds over moist areas. The Camassia
quamash seeds were small and black, and prefer sites that are moist and dry out over spring so
we used a similar method as the Carex species (except no wind scattering). Evenly distributed
except more heavily seeded near the moist areas.
Final Installation
The list of species of plants that our team had decided to use on our restoration site went through
several stages of revision. The plant selection included a diversity of grasses and small flowering
plants, suitable for moist grasslands. Because our site was somewhat waterlogged and close to a
permanent water source, our team decided to lean towards water tolerant species than drier
grassland species. Initially, our team decided to use: Danthonia californica, Lupinus latifolius,
Camassia quamash, Deschampsia cespitosa, Elymus glaucus, Festuca romeri, Carex inops, and
Grindelia integrifolia. However, after realizing that our site would become dryer in the summer,
we decided against Grindelia integrifolia. Also, we were able to obtain Festuca idahoensis
through the class source, instead of the Festuca romeri. Carex pachystachya was used in the
place of Carex inops. We had to reduce the number of Danthonia californica and Elymus
glaucus because the other groups had also ordered these plants, but we received an unexpected
windfall of Deschampsia Cespitosa from the class source.
Challenges and Limitations
As previously mentioned in this paper, Union Bay Natural Area was not always the open space it
is today. The site was a landfill in commission until the late sixties and subsequently capped with
clay to contain the garbage. This soil is so clay heavy that water drains very poorly and pools in
low spots throughout the site. Much of this winter has been extremely wet, and the weekend we
put our plants in the ground was no exception. This became a major driver in the way we
organized our planting actually because the middle of our plot had a few inches of standing mud
puddles. The soil was so inundated with water that it was hard to justify planting much there,
because although we picked plants that were somewhat water tolerant they would not likely
survive in a puddle of mud. The condition of our site affected almost all of our work, as
removing work and building the mounds was all made more difficult by the large pit of muck in
the middle of our plot. Also, on the topic of the limitations we would be remised not to mention
the budget constraints of this project and the availability of plants. We had to change some of the
species we had originally selected to better fit into the overall plant order we were making as a
class. Essentially the challenge we faced was to plant a palette of plants tolerant of drought in the
summertime yet tolerant of very wet soils in the wintertime. Also it was important for us to
properly prep the site and remove all the roots present so our plants had the best chance to thrive.
Project Monitoring
Final Plant Selection
Plant List
Species Number & Cost Source
Camassia quamash
Common Camas
2 packets with 100
seeds in each, $5
Inside Passage
Carex pachystachya
Thick-Head Sedge
1 ¼ pot, $14
Inside Passage
Danthonia californica
California danthonia
2 half-gallon pots, $4 UW SER
Deschampsia cespitosa
Tufted Hairgrass
6 half-gallon pots and
2 trays, $12
UW SER
Elymus glaucus
Blue Wild Rye
2 half-gallon pots and
8 3.5” pots, $46
UW SER &
Woodbrook
Festuca idahoensis
Idaho fescue
1 tray, $0 UW SER
Lupinus latifolius
Broadleaf Lupine
2 packets with 100
seeds in each, $5
Inside Passage
Plant Adaptations:
Each plant has unique adaptations that make these selections suitable for our site.
● Camassia quamash (Common Camas): Native. One of the two non-grass species on our
plot. Enjoy wet meadows that are damp in the winter and dry in the spring, just as our site
will act. Flowers bloom in the spring, which will encourage pollinators to our site. (UW
Plant Data Sheet)
● Carex pachystachya (Thick-Head Sedge): Native. These plants are excellent wetland
colonizers, and should do well in our open and damp site. Thrives in clay soil, which our
site is based on. Seeds are a good source of food for native bird species. (USDA Plant
Guide)
● Danthonia californica (California Oatgrass): Native. Occurs in Festuca dominated
grasslands, and prefers dryer soils to moist soils. These plants are stress tolerators and
survive well through droughts. (UW Plant Data Sheet)
● Deschampsia cespitosa (Beringian Hairgrass): Native. These plants prefer moist
meadow ecosystems, but are very adaptable to different climates across the northwest.
The seeds act as a food source for birds and are tall enough to provide cover for habitat.
(Burke Biology Herbarium)
● Elymus glacus (Blue Wildrye): Native. Occurs in both moist and dry meadows, and is
drought tolerant. Enjoys floodplain and stream edge habitats and acts as a good stabilizer
of soil. Seeds drop in the fall, another source of food for native animals. (UW Plant Data
Sheet)
● Festuca idahoensis (Idaho Fescue): Native. Grassland and sagebrush meadows are its
preferred habitat. Seeds are very viable and spread well to colonize new areas. Prefers
silty soils and grows well in elevated, exposed areas. (USDA Plant Guide)
● Lupinus latifolius (Broadleaf Lupine): Native. One of the two non-grass species on our
plot. These plants grow best in open forest meadows. Flowers bloom in spring, and
attract pollinators. A variety of soil types are suitable for lupine growth. (Burke Biology
Herbarium)
Before planting, our team considered what sorts of environment our plot provided and where
each species would thrive the best and where each could make the most improvements to our
site. While designing the site, we intentionally created a gradient of slope and moisture levels:
creating three mounds of high, medium, and lower heights; regions of flat and dry soil, and flat
and moist soil; and a slight slope descending from the mounds to the wet regions.