Uplands and Slopes: South Slope

Description

Figure 1: The South Slope

North is to the top. (Source: Green Seattle Partnership Reference Map on ArcGIS.com.)

North is to the top. (Source: Green Seattle Partnership Reference Map on ArcGIS.com.)

The South Slope is the slope just north of the South Plateau. It connects the main body of the park with the South Plateau. The northern border of the South Slope is the south loop social trail to the west and the Headwaters Bowl to the east. The southern border is a mixture property lines and the South Plateau.

Some trees in the South Slope have received ivy survival rings. There has been some planting at the lower reaches of the east section of the South Slope, along the border to the Headwaters Bowl. Other than that, the South Slope has received little or no attention.

The South Slope is split by a very steep social trail that connects the South Plateau to the rest of the park. During the dry months, this trail is very fragile and breaks into powder. During the rainy months, it is more stable but also more slick. The two sides of the trail also have different water regimes and different levels of invasive species. Because of this, the trail splits the South Slope into two subareas. This is the only HMU subdivision not based on who can do the work.

The lower reaches of Subarea A (Figure 2, below) are accessible to forest stewards. The trailside reaches of Subarea B are accessible to all volunteers. These are very small sections in the South Slope. Because the South Slope has the steepest slopes in the park, the vast majority of it is accessible only to Natural Area Crew.

The South Slope has less than 1% conifer cover and no observed regeneration of any trees. The canopy is mostly Acer macrophyllum, with 75% percent cover.

The target forest type for the South Slope is Tsuga heterophylla – Pseudotsuga menziesii/Polystichum munitum – Dryopteris expansa (Western hemlock – Douglas fir/Sword fern – Spreading wood fern; TSHE-PSME/POMU-DREX). The reference ecosystem is Mesic-moist conifer and conifer-deciduous mixed forest.

Water Flow

Subarea A (Figure 2, below) is above a number of seeps in the Headwaters Bowl that feed into the stream. These seeps flow over gleyed soils. Water and soil movement has been observed in these seeps even in high summer. The slopes above the seeps might receive some attention from the Stewardship Grant, but most attention will focus on the Headwaters Bowl and the Central Valley (as discussed in Stewardship Grant).

Subarea B receives the run off from the South Plateau. It is critical that we explore this area during a heavy rain. There is evidence that the run off from the South Plateau is eroding a section of the south loop social trail and affecting the immediately adjacent section of the Central Valley. How the runoff is affecting the slope, underneath the ivy, needs to be examined. Please see Uplands and Slopes: South Plateau and Water Flow: South Plateau Street Runoff for further discussions of water flow issues affecting the South Slope.

Vegetation

To the west side of the trail (left in the figure below), the South Slope is heavily invaded, with mature Alnus Rubra (Red alder) and Acer Macrophyllum (Big leaf maple) standing above a near-monoculture of Hedera helix (ivy). There is some remnant Polystichum munitum (Sword fern) and a stand of Rubus parviflorus (Thimbleberry).

On the east side of the trail, the section bordering the Headwaters Bowl and the Olympic Terrace properties is less invaded. The canopy mixture is the same, with more sword fern. This area has received some planting during restoration work. There is still a low diversity of native plants.

There has been no systematic plant survey in the South Slope HMU. Table 1, below, lists those plants that have been observed growing there through casual observation or have been planted during restoration activities. It also includes plants listed in the target forest type description but not observed or planted.

Table 1: Vegetation in the South Slope

Scientific Name Common Name Inv TFT So. Slope
Abies grandis Grand Fir   1  
Acer circinatum Vine maple   1  
Acer macrophyllum Big Leaf Maple   1 G
Alnus rubra Red Alder   1 G
Athyrium filix-femina Lady Fern   1  
Blechnum spicant Deer Fern   1  
Bromus vulgaris Columbia brome   1  
Carex deweyana Dewey’s sedge   1  
Cicerbita muralis Wall lettuce 1   G
Corylus cornuta Beaked Hazelnut   1  
Daphne laureola Spurge Laurel 1   G
Dryopteris expansa Spiny Wood Fern   1  
Galium triflorum Sweet-scented bedstraw   1  
Gaultheria shallon Salal   1  
Geranium robertianum Herb robert 1   G
Hedera helix English Ivy 1   G
Ilex aquifolium English Holly 1   G
Lapsana communis Nipplewort 1   G
Mahonia nervosa Dull Oregon-grape   1 G
Polystichum munitum Sword Fern   1 G
Pseudotsuga menziesii Douglas-fir   1  
Pteridium aquilinum Bracken Fern   1  
Rubus armeniacus Himalayan Blackberry 1   G
Rubus parviflorus Thimbleberry     G
Rubus spectabilis Salmonberry   1  
Rubus ursinus Trailing blackberry   1 G
Sambucus racemosa ssp. pubens Red Elderberry   1  
Thuja plicata Western red-cedar   1  
Tiarella trifoliata Threeleaf foamflower   1  
Trientalis borealis ssp. latifolia Western starflower   1  
Trillium ovatum Western Trillium   1  
Tsuga heterophylla Western Hemlock   1  
Urtica dioica Stinging Nettle     G
Vaccinium parvifolium Red Huckleberry   1  
Vancouveria hexandra Inside-out Flower   1

Key: “1” in Inv column indicates the plant is considered invasive. “1” in TFT column indicates the plant is listed in the Target Forest Type description for the 91st St. Slope. “G” or “R” in the So. Slope column indicates the plant has been observed growing or has been planted as part of restoration activities.

14 plant species have been observed growing in the South Slope HMU. Of these, seven (50%) are invasive. Of the 26 plants listed in the target forest type, five (19%) have been observed growing in the South Slope HMU.

Invasive Removal and Restoration Plan

Figure 2: The South Slope

Subarea A is to the east; Subarea B is to the west.

Subarea A is to the east; Subarea B is to the west.

Subarea A

Subarea A lies between the property lines of Olympic Terrace and the Headwaters Bowl. This means it will be affected by the work done in Subarea D of the Headwaters Bowl. It also lies above the seeps in the HWB that will receive some of the attention of the Stewardship Grant. Work here will have to be coordinated with these other projects.

The northern reaches of Subarea A have received numerous tree and shrub plantings in the last two years. These appear to have established well. Unfortunately, we did not keep accurate records, so we do not have accurate mortality rates.

In the parts of Subarea A that have been explored, there are few invasive plants. The efforts here will be to control what invasiveness is there and add to diversity, particularly at the shrub and groundcover layers.

Suggested Tasks for Subarea A:

  • Continue exploration and control of existing invasives. This can be done by forest stewards.
  • Monitor plantings for survival and growth. Replenish as necessary. Plant trees for buttressing in the lower sections; above that, plant shrubs for diversity and to maintain view corridors into the park from Olympic Terrace.
  • Coordinate work in Subarea A with the Stewardship Grant from the Washington Native Plant Society (HWB Subarea B) and with the homeowners of Olympic Terrace (HWB Subarea D) as necessary.

Subarea B

Trailside reaches of Subarea B are accessible to forest stewards and volunteers. There is a stand of Rubus parviflorus (Thimbleberry) along the trailside that can be spread through berry spreading and live staking.

Suggested Tasks for Subarea B:

  • Spread the Rubus parviflorus (Thimbleberry) with a mixture of berries and live stakes.
  • Attend to the trailside weeds such as Lapsana communis (nipplewort) and Cicerbita muralis (wall lettuce).
  • Subarea B cannot receive crew attention until water control efforts on the South Plateau have improved.

Uplands and Slopes: 91st St. Slope

Description

The 91st St. Slope is a long, narrow strip that runs between the main social trail at the lower end and property lines at the upper. It is 23,313 square feet. Because of its steepness, it’s relatively unexplored.

The southeast corner is known as “Knotweed Hill” because it had a thicket of Reynoutria japonica (Japanese knotweed) that was treated in 2012. There is some knotweed resurgence that has been reported and is being monitored. For the full story of Knotweed Hill, please see “Park and Restoration History.”

The majority of the 91st St. Slope has no conifer canopy and less than 1% conifer regeneration. However, at the north end, where the 91st St. Slope abuts the 92nd St. wetlands, there is close to 10% Tsuga heterophylla (Western hemlock).

The target forest type for the 91st St. Slope is Tsuga heterophylla – Pseudotsuga menziesii/Polystichum munitum – Dryopteris expansa (Western hemlock – Douglas fir/Sword fern – Spreading wood fern; TSHE-PSME/POMU-DREX). The reference ecosystem is Mesic-moist conifer and conifer-deciduous mixed forest.

Water Flow

One section of the trail bordering the 91st St. Slope dips below the water table. No other water flow has been observed from the 91st St. Slope.

Vegetation

Trailside, there are canopy gaps along this HMU that encourage the growth of blackberry and even grasses. There are dense laurel thickets, which were treated in the summer of 2014 with stem injection. Most of the rest of the trailside vegetation is Rubus armeniacus (blackberry) with Hedera helix (ivy) and some Rubus ursinus (trailing blackberry).

In October, 2012, three Alnus rubra (Red alder) trees fell from the 91st St. Slope across the main social trail and into a laurel thicket. This enlarged a canopy gap and blocked the trail until February, 2013, when it was cleared by the Natural Area Crew.

Because of the steepness of the rise from the trail, it’s difficult to see what is on the slope. The 91st St. Slope still has some trees that need ivy survival rings, but they are on nearly vertical sections of the slope.

No systematic monitoring has been done for the 91st St. Slope. However, what we have observed growing is listed in Table 1, below. Please see the key below the table for an explanation.

Table 1: Plants observed growing on the 91st St. Slope.

Scientific Name Common Name Inv TFT 91st Slope
Abies grandis Grand Fir   1 R
Acer circinatum Vine maple   1  
Acer macrophyllum Big Leaf Maple   1 G
Alnus rubra Red Alder   1 G
Asarum caudatum Wild ginger     R
Athyrium filix-femina Lady Fern   1  
Blechnum spicant Deer Fern   1  
Bromus vulgaris Columbia brome   1  
Carex deweyana Dewey’s sedge   1  
Claytonia sibirica var. sibirica Siberian spring beauty     G
Corylus cornuta Beaked Hazelnut   1  
Daphne laureola Spurge Laurel 1   G
Dryopteris expansa Spiny Wood Fern   1  
Galium aparine Bedstraw     G
Galium triflorum Sweet-scented bedstraw   1  
Gaultheria shallon Salal   1  
Hedera helix English Ivy 1   G
Hydrophyllum tenuipes Pacific Waterleaf     G
Ilex aquifolium English Holly 1   G
Impatiens glandulifera Policeman’s helmet 1   G
Lonicera involucrata Twinberry     R
Mahonia nervosa Dull Oregon-grape   1 G
Malus fusca Pacific Crab Apple     R
Oemleria cerasiformis Osoberry (Indian plum)     G
Osmorhiza berteroi Sweet Cicely     G
Polystichum munitum Sword Fern   1 G
Pseudotsuga menziesii Douglas-fir   1  
Pteridium aquilinum Bracken Fern   1  
Ranunculus repens Creeping buttercup 1   G
Reynoutria japonica Japanese Knotweed 1   G
Rosa gymnocarpa Baldhip rose     R
Rosa nutkana Nootka rose     R
Rubus armeniacus Himalayan Blackberry 1   G
Rubus spectabilis Salmonberry   1 G
Rubus ursinus Trailing blackberry   1 G
Rumex occidentalis Western dock     G
Sambucus racemosa ssp. pubens Red Elderberry   1 G
Taxus brevifolia Pacific Yew     G
Thuja plicata Western red-cedar   1 G
Tiarella trifoliata Threeleaf foamflower   1  
Tolmiea menziesii Piggyback Plant     G
Trientalis borealis ssp latifolia Western starflower   1  
Trillium ovatum Western Trillium   1  
Tsuga heterophylla Western Hemlock   1  
Urtica dioica Stinging Nettle     G
Vaccinium parvifolium Red Huckleberry   1  
Vancouveria hexandra Inside-out Flower   1

Key: Bold plant names indicate plants listed in a target forest type but not observed growing in any HMU. “1” in Inv column indicates the plant is considered invasive. “1” in TFT column indicates the plant is listed in the Target Forest Type description for the 91st St. Slope. “G” or “R” in the 91st St. Slope column indicates the plant has been observed growing or has been planted as part of restoration activities.

Of the 30 plant species observed growing in the 91st St. Slope HMU, seven (23%) are invasive. Of the 26 plants listed in the target forest type for the 91st St. Slope, nine (34.6%) are found growing in the HMU. These numbers would probably change with systematic observation.

Invasive Removal and Restoration Plan

Figure 1: 91st St. Slope

A: Accessible to volunteers. B: Contract Crew.

A: Accessible to volunteers. B: Contract Crew.

Subarea A

Subarea A measures 9,400 square feet and is accessible to all volunteers. It is separated from a similar volunteer-accessible area in the Central Valley HMU by a narrow social trail.

EarthCorps, in the fall of 2013, did some invasive removal in the Central Valley adjacent to the 91st St. Slope, reaching to about the dogleg in Figure 1, above.

In the winter of 2014, Friends of North Beach Park leap-frogged this restored area and cleared about 800 square feet on both sides of the trail of blackberry brambles.

Our intention was to continue clearing back towards the EarthCorps-cleared area over the summer months. However, in May and June we instead worked on aftercare for plants installed in dryer areas of the park, particularly near the entrance. In August, we did some re-clearing because the area had had a resurgence of invasives, particularly Ranunculus repens (creeping buttercup).

In August, a contract crew from the Parks Department injected a laurel stand with herbicide.

In November, Friends of North Beach Park cleared and planted in the area. Most of the plants were installed on the Central Valley side of the trail.

Suggested tasks for Subarea A:

  • Survey the area to be cleared between where the Friends of North Beach Park worked in January 2014 and EarthCorps worked in Fall of 2013.
  • Plan a series of public and forest steward workparties to bring the two areas together.
  • Work closer to the trail during wet weather, move to the streambank in the summer.
  • Use burlap and mulch to cover bare areas.
  • Use GSP provided plants to fill in in the fall.

The tasks above were written in the summer of 2014. As of the fall of 2014, work on the 91st St. Slope has been demoted in favor of concentrating on the Headwaters Bowl.

Subarea B

Subarea B is unexplored as of fall 2014. It is lower priority than the South or West Slopes, which have a much higher extent of invasion; consequently, there is no crew time scheduled or predicted for this subarea.

Suggested tasks for Subarea B:

  • Explore as much as possible.
  • Put survival rings on any trees that need them.

References

Green Seattle Partnership, 2014. GSP Reference Map on ArcGIS.com. http://www.arcgis.com/home/webmap/viewer.html?webmap=9be9415001144aa383e5b86e481d2c45&extent=-122.5312,47.374,-121.7945,47.7577 Dates of accession various.

#GivingTuesday for North Beach Park

#GivingTuesday is a chance to recognize volunteers and change makers at every level, from people working nationally to people working in your neighborhood. Today we ask you to recognize Friends of North Beach Park by making a tax-deductible donation to the Seattle Parks Foundation. Every dollar donated is a strong gesture of support for our efforts. All the money goes directly to the restoration of North Beach Park.

Why should you support Friends of North Beach Park? Here are a few reasons:

By the end of the planting season we’ll have planted well over a thousand plants. We’ve logged hundreds and hundreds of volunteer hours, and moved into new areas of restoration while maintaining previously-restored areas. We started working in the South Plateau again, and will do planting there in January. We’ve worked closely with Parks Department, Forterra, Seattle Public Utilities, and other agencies. We’ve had students from Seattle Pacific University, North Seattle College, Edmonds Community College, and the University of Washington volunteer and study in the park. We’ve had ten work parties, large and small — from more than 20 people to just three. In addition, three lead forest stewards work in the park four Mondays out of five.

We tabled at “Art in the Garden” again and, as ever, enjoyed the weather, food, and the great chance to meet neighbors of the park.

The work of Friends of North Beach Park was recognized by Groundswell NW in bestowing Luke McGuff one of two “Local Hero” awards, for work in sustaining and improving NW Seattle open space. We were also recognized by the Washington Native Plant Society in awarding us a Stewardship Grant of $500, which we have used for purchase of bare-root plants. Last but not least, Luke completed his Master of Environmental Horticulture program at the University of Washington, which resulted in a Restoration Management Plan being posted here chapter by chapter.

All of this work is accomplished by volunteer labor — hundreds, if not thousands, of hours a year. But even so, this work needs money — for purchase of plants, tools, and materials. We’re a small organization, so even a small donation will have a large impact.

Uplands and Slopes: North Slope

Description

The North Slope starts at the main entrance to the park and runs between the main trail and NW 90th St., as it rises up to 25th Ave. from 24th Ave. At 1.14 acres, it is the third largest HMU in North Beach Park.

The trail side has vertical stretches, with bare dirt and roots exposed. These stretches occasionally have heavy trees on top of them. These have been protected with wattles (burlap sacks half-filled with woodchips) held in place with ninebark stakes.
Further into the park, some of the trailside reaches of the slope widen out and become more volunteer accessible. There is still a lot of slope above the accessible areas, however.

The percent tree cover is about 85% deciduous, almost exclusively Acer macrophyllum (Big leaf maple); 5-10% is Thuja plicata (Western red-cedar), and the remaining 5-10% is gaps. The regenerating tree cover is less than 5% deciduous and less than 1% conifer.

The target forest type for the North Slope is Tsuga heterophylla – Pseudotsuga menziesii/Polystichum munitum – Dryopteris expansa (Western hemlock – Douglas fir/Sword fern – Spreading wood fern; TSHE-PSME/POMU-DREX). The reference ecosystem is Mesic-moist conifer and conifer-deciduous mixed forest.

Water Flow

The coniferous tree canopy over most of the North Slope is dense enough that it intercepts most of the water that would fall onto the slope. However, there are places where water flows from the North Slope onto the main trail during heavy rains. The main trail could use some water bars to help deal with this situation.

Furthermore, there are bare places in the groundcover that should get some attention. See “Invasive Removal and Restoration Plan” below.

In the summer of 2013, the Parks Department Natural Area Crew put coir logs underneath the intersection of 90th St. and 25th Ave.

Figure 1: Coir logs on the North Slope.

Side view of erosion control. A narrow trench was dug at the top of the slope, the netting was laid in and staked with 2x2 stakes, and then the trench was reburied.

Side view of erosion control. A narrow trench was dug at the top of the slope, the netting was laid in and staked with 2×2 stakes, and then the trench was reburied.

Vegetation

No invasive plants had established an area of monoculture on the North Slope. What is visible from the trail is a canopy of Acer macrophyllum (Big leaf maple) and a shrub layer of Polystichum munitum (Sword fern) and Mahonia nervosa (Low Oregon-grape). This association is encouraged through occasional spreading of Mahonia berries.

Observed during the belt transect (see below) was a stand of Holodiscus discolor (Ocean spray), the first observed in the main body of the park, and the only known instance of Stellaria crispa (Crisp sandwort) that we know of in the park. (Neither of these were in a transect plot.) The upper reaches of the North Slope have many daffodils, bluebells and other garden plants and escaped ornamentals.

The June, 2014 belt transect laterally crossed the North Slope; eight plots were established from the trailside up to the street end. See “Monitoring” for a full discussion of the belt transect protocol. Most of the area crossed by the transect had received some restoration, by volunteers at the lower end and Natural Area Crew at the upper end.

Table 1, below, shows the target forest type indicator species for the North Slope and all species found in our survey. Please see the Key, below the table, for a full explanation of the numbers.

Table 1: Target forest type and transect species for the North Slope

Binomial Common Name % Cover TFT Goal
Abies grandis Grand fir 0.06 14.00
Acer circinatum Vine maple 0.00 20.00
Acer macrophyllum Big leaf maple 83.88 18.00
Aesculus hippocastanum Horse chestnut 0.06 0.00
Alnus rubra red alder 11.25 9.00
Athyrium filix-femina Lady fern 2.00 2.00
Mahonia nervosa Dull Oregon-grape 11.38 4.00
Blechnum spicant Deer fern 0.00 2.00
Bromus vulgaris Columbia brome 0.00 2.00
Calystegia sepium false bindweed 0.13 0.00
Carex deweyana Dewey’s Sedge 0.00 2.00
Claytonia sibirica Siberian miner’s lettuce 0.38  
Corylus cornuta Beaked hazelnut 0.38 3.00
Cymbalaria muralis Kenilworth ivy 0.06 0.00
Dryopteris expansa Spiny wood fern 0.00 3.00
Eurhynchium oreganum Oregon beaked moss 0.13  
Galium aparine cleavers 0.44  
Galium triflorum Sweet-scented bedstraw 0.00 2.00
Gaultheria shallon Salal 0.00 2.00
Geranium robertianum Robert’s geranium 0.81 0.00
Geum macrophyllum Large-leaved avens 0.06  
Hedera helix English Ivy 1.63 0.00
Holcus lanatus velvet grass 0.06 0.00
Hyacinthoides hispanica Bluebells 0.13 0.00
Hydrophyllum tenuipes Pacific waterleaf 7.19  
Lapsana communis Nipplewort 0.75 0.00
Lunaria annua Silver dollar 0.13 0.00
Moss   1.63  
Mycelis muralis Wall lettuce 0.81 0.00
Oemlaria cerasiformis Indian plum 0.06  
Oenanthe sarmentosa Water parsley 0.13  
Osmorhiza berteroi Sweet cicely 0.31  
Polystichum munitum sword fern 12.88 54.00
Prunus avium Bird cherry 0.63 0.00
Pseudotsuga menziesii Douglas-fir 0.00 45.00
Pteridium aquilinum var. pubescens Bracken fern 0.00 3.00
Ranunculus repens Creeping buttercup 0.06 0.00
Ribes sanguineum Red flowering currant 0.19  
Rubus spectabilis Salmonberry 0.06 4.00
Rubus ursinus Trailing blackberry 0.19 3.00
Sambucus racemosa Red elderberry 0.06 2.00
Symphoricarpus albus Snowberry 0.13  
Taraxacum officinale ssp. officinale Common Dandelion 0.06 0.00
Tellima grandiflora Fringecup 0.19  
Thuja plicata Western red-cedar 0.00 33.00
Tiarella trifoliata var. trifoliata Threeleaf foamflower 0.00 5.00
Tolmiea menziesii Piggyback 0.75  
Trientalis borealis ssp. latifolia Western starflower 0.00 1.00
Trillium ovatum Western trillium 0.06 1.00
Tsuga heterophylla Hemlock 0.06 36.00
Urtica dioica Stinging nettle 12.00  
Vaccinium parvifolium Red huckleberry 0.00 3.00
Vancouveria hexandra Inside out flower 0.00 7.00

Key: “0.00” in Pct. Cover column indicates a target forest type indicator species not found during the survey. No value in the TFT Goal column indicates a native species not listed in the target forest type. “0.00” in the TFT Goal column indicates an invasive species to be removed.

Invasive Removal and Restoration Plan

Figure 2: North Slope

A: Trailside, less-steep area accessible to volunteers. B: Slope area to be worked on by Natural Area crew.

A: Trailside, less-steep area accessible to volunteers. B: Slope area to be worked on by Natural Area crew.

Subarea A

Subarea A measures approximately 13,200 feet. Volunteers can work in the trailside sections and along some of the more gradual slopes at the western edge. Of particular interest are gullies and washes that form from the steeper parts of the slope. These could be controlled with dikes and careful live staking and planting at the lower sections, and coir logs or other erosion control methods above. The soil in these washes is uncompacted, and likely to slip if too heavily stepped on.

Trailside sections of Subarea A have received plantings every year, by both Natural Area Crew and volunteers. The western edge of Subarea A has received plantings of Abies grandis (Grand fir) and Tsuga heterophylla (Western hemlock).

Suggested tasks for Subarea A:

  • Continue spreading Mahonia grapes, as possible.
  • Add dikes and wattles to areas experiencing erosion. Live stake above the wattles.
  • Plant trees along the lower reaches of the slopes to provide buttressing.

Subarea B

Subarea B measures nearly 36,400 square feet. The rim along 90th St. has received some plants and mulch from volunteers. Below the rim, the Parks Department Natural Area Crew did invasive removal (by hand), erosion control, and planting in 2013.

Forest stewards can visually monitor this area from the street rim and the trail, but further work in this area will have to be done by the Natural Area Crew.

References

Green Seattle Partnership, 2014. GSP Reference Map on ArcGIS.com. http://www.arcgis.com/home/webmap/viewer.html?webmap=9be9415001144aa383e5b86e481d2c45&extent=-122.5312,47.374,-121.7945,47.7577 Dates of accession various.

Uplands and Slopes: South Plateau

Description

The South Plateau is an isolated upland with a separate, unofficial entrance. From the main body of the park, it is only accessible via a steep social trail that is slippery in the winter and friable in the summer. If you think of North Beach Park as a boot, the South Plateau is the heel. The floor of the plateau is surrounded by steep, short walls.

The South Plateau, at 25,000 square feet, is also the largest flat area in the park. As explained in “Park and Restoration History,” the South Plateau was intensively cleared in the summer of 2012 by an independent forest steward.

For more than a year, the only work done in the South Plateau was by Parks Department Natural Area Crew. In the summer of 2014, forest stewards watered and did some after care for the plants in June and July, and there was a work party in September.

The South Plateau has less than 1% conifer cover, but at least 75% deciduous cover.

The target forest type for the South Plateau is Tsuga heterophyllaPseudotsuga menziesii/Polystichum munitumDryopteris expansa (Western hemlock – Douglas fir/Sword fern – Spreading wood fern; TSHE-PSME/POMU-DREX). The reference ecosystem is Mesic-moist conifer and conifer-deciduous mixed forest.

Water Flow

During the rainy season, water accumulates from NW 85th St. and 26th Ave NW (310 feet) (all elevations from Seattle DPD GIS map). It runs to the north uninterrupted by any green scape or drainage system the length of 26th Ave. to 88th St., where it turns to the west. Once at 27th Ave., it turns again to the north and enters the park. The floor of the South Plateau is at 250 feet, giving this run about a 5% grade.

Figure 1: Path of water flow into the South Plateau.

The blue line indicates path of water, which flows toward the top of the map, from 85th St. to the South Plateau. (Source: Seattle Department of Public Development DPDGIS map.)

The blue line indicates path of water, which flows toward the top of the map, from 85th St. to the South Plateau. (Source: Seattle Department of Public Development DPDGIS map.)

Before clearing, the dense ivy and blackberry cover dissipated a lot of the energy of this water flow, spreading it out over the surface of the plateau. However, invasive removal caused a serious erosion problem was caused.

The Parks Department has installed rip rap and forced meanders into the water flow using plantings and fascines (water barriers made of bundles of salmonberry live stakes).

Figure 2: Water flow in May, 2014

Looking up towards the entrance of the park (the gray rocks in the upper right.) This is from about the middle of the fascines.

Looking up towards the entrance of the park (the gray rocks in the upper right.) This is from about the middle of the fascines.

There is still some water flow control to be done on the South Plateau, and it will have to be studied during rain events of different sizes during the fall and winter.

Water control can be improved in this area by adding meanders to the downstream end of the storm runoff, maintaining the existing meanders and fascines, and working with the stream to slow it down and let the water percolate through the plateau.

During the summer drought, the South Plateau has no water source. This leads the soil to dry and harden, becoming very compact. Plant establishment is very slow, but improving.

For more recent observations on South Plateau water issues, please see Water Flow: South Plateau Street Runoff.

Vegetation

At the start of restoration, the South Plateau was a mix of Acer macrophyllum (Big leaf maple) and Alnus rubra (red alder), with a shrub layer almost exclusively of Hedera helix (English ivy) and Rubus armeniacus (Himalayan blackberry). Other notable invasives included Lamium galeobdolon (Yellow archangel) and Clematis vitalba (Wild clematis).

There is still a fair amount of remnant and resurgent Hedera helix (ivy). Calystegia sepium (bindweed), Lapsana communis (nipplewort), and Geranium robertianum (herb robert) have also made inroads.

A forest monitoring plot following the Green City protocol was established in the South Plateau in July, 2012, and revisited in August, 2013. Note the difference, in Figures 3 and 4 below, in regenerative invasive trees. This is what happens with overclearing followed by neglect.

Figure 3: Invasive regenerative trees, South Plateau, 2012.

This was the extent of invasive trees in 2012, when the South Plateau was just starting to be cleared. (Source: EarthCorps, 2012)

This was the extent of invasive trees in 2012, when the South Plateau was just starting to be cleared. (Source: EarthCorps, 2012)

Figure 4: Invasive regenerative trees, South Plateau, 2013.

The South Plateau was cleared aggressively in 2012 and early 2013, and then neglected.

The South Plateau was cleared aggressively in 2012 and early 2013, and then neglected.

Invasive Removal and Restoration Plan

Figure 5: South Plateau.

A: Accessible to volunteers. B: Contract or Natural Area Crew. (Source: GSP Reference Map on ArcGIS.com)

A: Accessible to volunteers. B: Contract or Natural Area Crew. (Source: GSP Reference Map on ArcGIS.com)

Subarea A

Subarea A (outlined in blue in Figure 5, above), at 13,000 square feet, is the largest and driest flat area of the park and the most volunteer friendly. Even though it’s surrounded by Subarea B, it can be accessed by walking carefully down some rip rap. This was the area the independent forest steward and her crew worked in.

The over-clearing followed by neglect has left the South Plateau with a plant community that is still very much out of balance. It’s in better shape than when the ivy and blackberry dominated, but it’s still at risk of an invasive-only plant community.

There is still a lot of invasive removal in Subarea A, including annuals such as Lapsana communis (nipplewort). Subarea A could use a lot of wood mulch, both around the establishing plants, and in large areas of relatively bare ground. In the long term, this would ease the compaction of the soil and aid in plant establishment.

Suggested tasks for Subarea A:

  • Mulch around existing plants, and spread mulch to a depth of at least 4” in bare areas of South Plateau.
  • Monitor water flow during rain events. Adjust and repair fascines as necessary.
  • Add meanders to further reaches of South Plateau. The goal is to slow and spread the water, so it stays on the South Plateau and percolates into the soil.
  • Investigate mycelium inoculation as a means of improving soil conditions.
  • Forest stewards continue working in South Plateau one day a month for after care and weeding.
  • Have two work parties a year (one for planting, one for invasive removal and/or after care).

Subarea B

Subarea B is the walls surrounding the plateau part of the South Plateau. It measures approximately 12,000 square feet. The walls are nearly vertical, making it only available for work by the Parks Department Natural Area Crew. There is a rim of the plateau accessible from 27th Ave NW, but it is so narrow that the best approach is to have the Natural Area Crew work on the rim, and the forest stewards or volunteers do aftercare.

Either the Parks Department Natural Area Crew or the volunteers in the summer of 2012 (or both) have done some work on the western slope. On the eastern and southern slopes of the wall, property lines might be an issue.

Further work on Subarea B will be done by the Parks Department Natural Area Crew. Some of the work could be done at the same time as working on the South or West Slopes (see below).

Suggested tasks for Subarea B:

  • Remove resurgent invasives and increase density in cleared areas.
  • Remove ivy and put survival rings on trees on the northern edges of the South Plateau.
  • Coordinate work on the northern edges of the South Plateau with work done on the South Slope.

References

Department of Planning and Development. 2007. City of Seattle Department of Planning and Development GIS map. http://web1.seattle.gov/dpd/maps/dpdgis.aspx (Dates of accession various.)

EarthCorps. 2012. North Beach Park South Plateau Baseline Report. (unpublished document). EarthCorps, Seattle.

EarthCorps. 2013. North Beach Park South Plateau Monitoring Report. (unpublished document). EarthCorps, Seattle.

Green Seattle Partnership, 2014. GSP Reference Map on ArcGIS.com. http://www.arcgis.com/home/webmap/viewer.html?webmap=9be9415001144aa383e5b86e481d2c45&extent=-122.5312,47.374,-121.7945,47.7577 (Dates of accession various.)

North Beach Park Week in Review

It’s been a busy week at North Beach Park!

It started last Sunday (16th), when Friends of North Beach Park forest steward Morry (who also works at Llandover Woods) arranged for the forest steward from Llandover, Glenn, to bring some equipment to North Beach Park so we could shoot a video.

Drone
Here is a picture of one of the drones being stabilized before takeoff.

And here is the resultant video:

NorthBeachNovember1080 from Glenn Austin on Vimeo.

I recommend full screen, of course. And turn off any other music so you can hear the wonderful guitar piece Glenn selected for the video.

Making the video was fun, and the results certainly can’t be beat. Now I want to do one every season — easy for me to say, of course, I don’t have to do any of the work. ;> (There are more photos on Flickr.)

Here is a video Glenn made of Llandover Woods.

On Monday, Drexie, Tad, and Luke prepared the plants for the work party. This involved sorting, revising the planting plan, figuring out which was which and what was what, and tagging everything.

Here are Tad (left) and Drexie (center background) tagging the plants:
Tad (left) and Drexie (center background) tagging plants

We took the plants to North Beach and left them in a staging area down the trail. We also saw, much to our dismay, that someone — between Sunday afternoon and Monday morning — dumped at least 43 cans of paint in North Beach Park. The ones I picked up were all full. The Ballard blog posted an article about it. It’s nice to see that most of the comments are upset about the dumping.

The paint cans were pretty quickly picked up, probably Tuesday (thank you, Seattle Parks Department!). But still, considering where they were, someone went to more trouble to dump them in the park than it would have taken to get rid of them legitimately. (Guess what — more photos on Flickr.)

And Saturday was our planting party. In addition to the plants from the Green Seattle Partnership, we had eight Sitka Spruce and one Western Red Cedar provided by a neighbor.

We had help from the iCARE students from North Seattle College again:
iCARE

And we were also joined by students from Circle K International from the UW:
Circle K International

We planted more than 100 plants, and this included a fair amount of prep work for some of the areas. It was a very successful work party.
Plants ready for installation

Our next work party won’t be until January. But there are still work parties at Golden Gardens, Carkeek Park, and Llandover Woods.

November Work Party!

November is the second of FOUR planting work parties in North Beach Park. We hope to plant just over 1000 plants (total). Join us for this quest and help make North Beach Park even better.

Saturday, November 22: We’ll be working in an area that was cleared last winter. Now it needs some extra attention before being planted, so this will be a mixture of a work party. We’ll clear the area first and then plant – 72 plants. It all should go rather quickly.

We’ll meet at 9 a.m. at the main entrance to the park, 90th St. and 24th Ave. NW. We’ll go until 12 noon.

At this work party, Friends of North Beach Park will be joined again by students from North Seattle’s iCARE program for international students, and students from the University of Washington Circle K International.

Please sign up in advance so we know you’re coming.

Remember to wear weather-appropriate layers that can get dirty and bring water or a snack if you need them. We provide tools, gloves, and guidance. All ages are welcome; volunteers under 18 must sign and bring a waiver (available online). The #40 and #48 buses stop within a few blocks of the park, check Metro for details. Parking is available on 90th St. east of 24th.

November 22 will be the first of two planting work parties installing plants provided by Green Seattle Partnership and Seattle Department of Parks and Recreation. On January 24, we return to the South Plateau for more GSP plant installation. The last planting work party will happen on February 28, when we install shrubs and small trees in the wetlands provided by the Washington Native Plant Society stewardship grant.

As always, if you don’t have the time to join us for a work party, you can support Friends of North Beach Park by making a directed donation to the Seattle Parks Foundation.

All money donated will be used to fund the restoration efforts of North Beach Park.

If you have any questions, feel free to write lukemcguff[at]yahoo.com for further information.

Water flow: South Plateau Street Runoff

(This the first of two posts about street runoff in North Beach Park.)

There are two ways that water enters North Beach Park. The main way, which lasts all year long, is by numerous, broad, horizontal groundwater seeps. Most of these come into the park from the south wall of the ravine; some enter the park from the base of the 24th Ave. slope. These provide a steady flow that has lasted through record droughts. The seeps move very slowly, and do not form channels.

The other way water enters the park is through flashy events triggered by rainstorms. We’re still investigating these water flows. This water enters the park from two locations, the South Plateau and a culvert from 24th Ave. located at the southeast corner of the park.

The first we knew of is the water flow from the South Plateau. The water accumulates for several blocks before it enters the park; by then, it is a narrow, fast flowing stream. Before the South Plateau was cleared, this water hit a dense mat that was a mixture of blackberry and English ivy. It might be that this dense mat dissipated the energy enough to avoid channelizing and erosion.

In the summer of 2012, volunteers cleared the South Plateau in a series of weekly work parties. They also installed a stairway, hoping to create a native plant demonstration garden. The stairway was at the very point that the street runoff entered the park. When we found out how much water was flowing into the park, the project was abandoned and the South Plateau was neglected by forest stewards until the summer of 2014.

Street Runoff
The photo above is from October, 2012, and shows the runoff sheeting over the steps.

South Plateau Street Runoff
The photo above is from December, 2012. You can see how straight the channel is already. There had been little planting so far, and no attempt had yet been made to control or slow the water.

In the spring and summer of 2013, Parks Department crews installed rip rap at the entrance to the park. They dismantled the staircase and replaced it with a series of coir logs forming terraces. Past the rip rap and the coir log terraces, the crews installed meanders and fascines into the channel, to slow the water down and give it more opportunity to percolate into the soil.

On October 31, 2014, two forest stewards (Luke and Tad) visited the South Plateau at the tail end of a rain storm. It had rained nearly 1 3/4″ in the previous 36 hours according to a rain gauge in Tad’s back yard. This part of the post incorporates Tad’s notes from our visit.

Most of the street runoff was flowing into the park via the rip rap. Some flowed past the rip rap and was absorbed by a large wood chip pile. (However, this is a temporary feature.)

Street runoff
The above picture shows the flow as the rain was tapering off. The flow is much slower for various obstructions and meanders, but does not stay on the plateau long enough to sink in.

Street runoff
At the west end of the plateau, the water runs underneath some wattles the three of us installed in May. It flows down to the main body of the park. We still need to observe the runoff in the main body of the park during a heavy rain.

Standing water
We also saw standing water or slowly moving water in many places in the South Plateau that were relatively far from the street runoff channel. Is there a clay layer near the surface? Is there something else that prevents water from percolating into the soil?

We still need to explore the South Plateau and North Beach Park during heavy rain. There are a couple places where we might be able to divert the street runoff to flow over the plateau and sink in before flowing over the edge. We also need to understand where the pooling water is coming from: Another runoff we don’t know about yet, or just rainfall?

Wetlands: Stewardship Grant

In June of 2014, Friends of North Beach Park received a $500 stewardship grant from the Puget Sound Chapter of the Washington Native Plant Society.

The main body of this chapter was written in summer of 2014. The “Addendum” section, following “Plant List” below, was written in November 2014, after some work had been done.

Purpose of grant

The purpose of the grant is to help rebuild the wetland basins of the park into a scrub-shrub plant community, with trees surrounding the wetlands to stabilize the upland slopes. The planting pallet will follow recommendations for the reference ecosystem, riparian forest and shrubland.

The replanting will be done in phases, using obligate wetland plants to begin holding the soil, followed by reintroducing woody plants to build deeper root structures.

Timeline (projected)

The timeline below was written in summer of 2014.

  • September: Invasive removal in the wetlands. This will be done by small groups of forest stewards. Care will be taken not to overclear an area and not to disturb the soil structure too much.
  • Early October: installation of obligate wetland plants. This is done just prior to rain return, so the ground is relatively stable. The work will be done by experienced forest stewards.
  • Late October: installation of facultative shrubs and woody plants at the wetland borders. This work can be done by volunteers during a regular Friends of North Beach Park work party.

For the timeline as the project is being executed, please see “Addendum,” below.

Plan

The work will be centered on the social trail dividing Headwaters Bowl Subarea B and Central Valley Subarea B. See Figure 1, below.

Figure 1: Area of work for the Stewardship Grant.

The projected work area for the WNPS Stewardship Grant.

The projected work area for the WNPS Stewardship Grant.

The stream will be the northern boundary. In the Central Valley, the southern boundary will be the south loop social trail. In the Headwaters Bowl, the southern boundary will be the wetland border established by Doug Gresham in 2011. This is the entire area referred to as “Central Valley Subarea B” and the western edge of the area referred to as “Headwaters Bowl Subarea B.” The actual work area will be smaller than illustrated above.

The planting is intended to increase diversity and density in three locations:

  • Mixture of shrub and herbaceous plants streamside.
  • Herbaceous plants in seeps.
  • Shrubs at the toe of the slopes, above the seeps.

Headwaters Bowl Subarea B

Streamside

The substrate of the stream in this location is mostly silt and fine sand, with occasional patches of small cobbles where the channel has narrowed.

There is a large Thuja plicata (Western red-cedar) stump in the stream, covered with moss and hosting numerous Vaccinium parvifolium (Red huckleberry). This could host some Cornus canadensis (Canadian dwarf dogwood) but would be unlikely to support Tsuga heterophylla (Western hemlock).

Plants already growing streamside (based on a visual survey):

  • Rubus spectabilis (Salmonberry)
  • Lysichiton americanum (Skunk cabbage)
  • Oenanthe sarmentosa (Water parsley)
  • Carex amplifolia (Broad-leafed sedge)
  • Polystichum munitum (Sword fern)
  • Athyrium filix femina (Lady fern)
  • Urtica dioica (Stinging nettle)
  • Sambucus racemosa (Red elderberry)
  • Tolmeia menziesii (Piggyback)
  • Cardamine hirsuta (Shotweed)
  • Lonicera involucrata (Twinberry)

Above the stream

About five feet above the stream, there is a nurse log and a large amount of coarse woody debris holding the stream bank. I think the seep is eroding the soil from underneath the CWD, and it will eventually collapse. Upland of this the substrate is mostly decayed wood, which makes it a good place for Tsuga heterophylla. On either side of this substrate, the seeps reach to the wall of the ravine.

Growing in this area:

  • Polystichum munitum (Sword fern)
  • Rubus spectabilis (Salmonberry)
  • Ilex aquifolium (Holly)
  • Hydrophyllum tenuipes (Pacific waterleaf)
  • Tolmeia menziesii (Piggyback)
  • Sambucus racemosa (Red elderberry)
  • Ribes bracteosum (Stink currant)
  • Spiraea douglasii (Douglas’ spirea)
  • Germanium robertianum (Herb robert)

Growing in the seep between the CWD area and the social trail:

  • Tolmeia menziesii (Piggyback)
  • Glyceria elata (Tall mannagrass)
  • Oenanthe sarmentosa (Water parsley)
  • Hydrophyllum tenuipes (Pacific waterleaf)
  • Rubus spectabilis (Salmonberry) in dryer areas
  • Thuja plicata (Western red-cedar) (planted)
  • Cardamine hursuta (shotweed)

Central Valley Subarea B

Streamside

The stream itself is similar to the stream in HWB Subarea B: The wider sections have a substrate of sand and fine silt, and with narrower sections have a substrate of small cobbles.

The red cedar stump in this section has a wider variety of plants than the one in the HWB section. In addition to the red huckleberry and mosses, there are also salmonberry and a Tsuga heterophylla (Western hemlock) seedling that is naturally regenerating.

Above the Stream

There is also a nurse log holding the bank, but there is not the woody debris substrate above it as with the HWB.

Salmonberry and red elderberry form a thicker canopy than on the HWB side. There is also much more Hedera helix (English ivy) that comes down from the South Slope and lies across the seeps.

In the stream, but closer to the right bank, is a red alder root ball, with the tree itself lying across the width of the seep. The root ball has red huckleberry, ivy, and a couple Acer macrophyllum (Big leaf maple) seedlings growing in it. There is holly in the stream and around the root ball that will need to be removed.

Integrating into Work Flow

Between Sept. 15 and Nov. 27, there are nine possible Monday sessions and the October work party. The September work party will be on the South Plateau, and the November work party will be dedicated to planting GSP-provided plants. It is possible that some work on the stewardship grant could take place at the November work party.

Plant list

Table 1, below, is the plant list submitted to the WNPS for the grant. The actual planting list will vary considerably from this list, but that variance is within the scope of the grant. The wetland status, size, and number were obtained from the Fourth Corner Nurseries Catalog.

Table 1: Plant list and estimated planting time.

Early October
Genus Common Name Wetland Size # plants
Carex deweyana Dewey’s sedge FAC bareroot 100
Carex obnupta Slough sedge OBL bareroot 100
Fraxinus latifolia Oregon ash FACW 6-12″ 50
Glyceria elata Tall mannagrass FACW bareroot 100
Viburnum opulus v. americanum Highbush cranberry FACW 3-6″ 50
Late October
Genus Common Name Wetland Size # plants
Holodiscus discolor Ocean spray FACU 6-12″ 50
Lonicera involucrata Black twinberry FAC 6-12″ 50
Berberis nervosa Low oregon-grape FACU 3-6″ 100
Sambucus racemosa Red elderberry FACU crown 50
Vaccinium parvifolium Red huckleberry FACU 2″ pots 50

OBL = obligate, plant has to grow in a wetland; FACW = facultative wetland, plant grows in a wetland most of the time but can occasionally be found in drier areas; FAC = facultative, plant grows equally well in wetlands and drier areas; FACU = facultative upland, plants grows mostly in drier areas, but can occasionally be found in wetlands.

For the purchased plant list and the actual planting times, please see “Addendum,” below.

Addendum

This is the revised timeline, written after some work had already been done.

  • Plants were ordered in October for October and February delivery.
  • The October plants were wetland obligate graminoids.
  • The February plants were facultative wetland shrubs and trees.
  • The plants will be installed during regular public work parties.

In October 2014, the following orders were placed with Fourth Corner Nursery, for delivery in October and February.

Table 2: October order of Obligate plants.

Scientific Name Common Name Wetland Quantity
Carex amplifolia (1) Broad-leaved sedge OBL 50
Carex stipata (2) Sawbeak sedge OBL 100
Deschampsia caespitosa (3) Tufted hair-grass FACW 50
Glyceria elata (1) Tall mannagrass FACW 100
Juncus ensifolius (2) Daggerleaf rush FACW 50
Scirpus microcarpus (3) Panicled bulrush OBL 100

1 = observed growing with limited distribution; 2 = introduced to North Beach Park with this planting; 3 = previously introduced by restoration planting.

Table 3: February order of Facultative Wetland Shrubs and Trees.

Scientific Name Common Name Wetland Quantity
Physocarpus capitatus (3) Pacific ninebark FACW 50
Fraxinus latifolia (1) Oregon ash FACW 50
Malus fusca (2) Pacific Crab Apple FACW 50
Salix lucida (2) Pacific willow FACW 50
Salix sitchensis (2) Sitka willow FACW 50

1 = observed growing with limited distribution; 2 = introduced to North Beach Park with this planting; 3 = previously introduced by restoration planting.

The October order is the actual quantities delivered and planted during the October work party. As discussed above, the work occurred in the Central Valley Subarea B and Headwaters Bowl Subarea B.

The planting was done by volunteers led by forest stewards. Duckboards were used to minimize disruption to the wetlands wherever possible.

The work area actually became larger than illustrated in Figure 1, above. Planting was done further east in Headwaters Bowl.

The second order will be delivered in time for the February work party (February 28, 2015). Approximately ten of each shrub will be held back for a year or so, to test is survival rates are increased with an extra year of nursery care.

The second planting will also happen further east than the original prospect in Figure 1.

Green Seattle Day This Saturday!

2014 Green Seattle Day

Your forest needs you! Join the Green Seattle Partnership on Saturday, November 8th, as we kick off planting season with a day of volunteerism in 21 parks throughout the City at the 9th Annual Green Seattle Day.

Our biggest event of the year, Green Seattle Day is a great chance for first-time and long-time volunteers to help grow the forest in their own city by planting trees and other plants in city parks. This year our main site will meet at the Rainier Beach Community Center (lunch included after planting), but there are 17 other locations around the city that need volunteers, so check out the full list here, pick your lucky park, and sign sign up now so that we can plan the best event for everyone.

To join us at the main site, sign up to volunteer at the East Duwamish Greenbelt, Kubota Gardens, Lakeridge Park, or Rainier Beach Urban Farm & Wetlands, and meet at the Rainier Beach Community Center at 9am.

The Ballard park hosting Green Seattle Day this year is Golden Gardens. Join forest stewards from Carkeek Park, North Beach Park, and of course, Golden Gardens to spruce up the place a little bit.

Salamander
[Photo from Green Seattle Day 2013 at Carkeek Park.]

Green Seattle Day is great for all ages. We’ll bring the gloves, tools, and all of the plants, you bring the helping hands! Coffee and snacks provided at all sites, so register early so that we can have enough for everyone. Please dress for the weather, and wear sturdy shoes that can get wet and a little dirty. This is our biggest party of the year and we want you there! More information available at www.greenseattle.org. Please contact Norah Kates at info@greenseattle.org, or call (206) 905-6943 with any questions.

Thanks, and we look forward to seeing you in the parks!