State of the Park and 2015 Plans

A bulleted list! So you know it’s precise! Considering each HMU where we did some work in 2014, starting with the South Plateau:

South Plateau

  1. Had been neglected since project dropped by previous forest steward.
  2. Neighbor complaints caused us to return to working on it.
  3. Water flow appears to be under control. One forest steward has examined it in the rain and observed that most of the water was flowing into a wood chip pile.
  4. Personal contact was made with two neighbors of the South Plateau, and a homeowner engaged in a gutting and refurbishing of a house. All contacts were positive.
  5. There was one work party in 2014, clearing and planting prep with SPU students.
  6. Issues:
    • Ivy, holly, blackberry, yellow archangel resurgence.
    • Nipplewort, wall lettuce, other annual weeds.
    • Water flow seems to be under control, but still needs to be inspected regularly during heavy rain.
    • Establishment and after care for already established plants.
    • Maintain neighbor relations.
  7. 2015 Plans:
    • January: Planting work party, 128 plants.
    • September: Clearing and prep for planting with SPU students.
    • Forest stewards will continue to work approximately one Monday a month, to maintain cleared areas and prevent reinfestation. We will also attempt to spread seeds of native plants as appropriate, particularly Dicentra Formosa (Pacific bleeding heart).

Central Valley:

  1. Began 2014 with clearing about 800 square feet, down the trail from Knotweed Hill. The clearing happened on both sides of the trail, so it was in both the Central Valley and on the base of the 91st St. Slope.
  2. The area was neglected during the summer months in favor of after care for plants in drier areas of the park – along the North Slope side of the main trail and along the 24th Ave. rim.
  3. A three person crew worked on the area during the August work party.
  4. This area will be planted in the November work party. There will be enough people there to do some clean up first.
  5. Extensive planting happened in the seeps at the eastern edge of the Central Valley during the October work party.
  6. 2015 plans: Forest stewards and work parties will monitor cleared areas to prevent invasive resurgence and provide after care as/if necessary.

91st St. Slope:

  1. In addition to the clearing mentioned above, a thicket of laurel was limbed by forest stewards early in the summer.
  2. This thicket was given both E-Z-Ject and cut and paint treatments to kill the laurel.
  3. Forest stewards will monitor this laurel thicket.

Knotweed Hill (Knotweed Hill is located at the border of the North Slope and the 91st St. Slope HMUs.)

  1. Knotweed Hill was treated for knotweed in the summer of 2014.
  2. There was some watering of the upland plants in the summer, but it has received no other attention.
  3. It needs to be monitored for invasive resurgence and any after care.

Headwaters Bowl (“HWB”):

  1. The narrow, western section of the HWB received about half the plants from the October work party. Some plants were put into bowl section as well.
  2. The area between the north side of the streambank and the main trail received a lot of clearing in 2013 from EarthCorps and Parks Dept. contract crew. These cleared areas need to be regularly inspected to prevent resurgence and to provide after care for plants installed in 2013.
  3. An area of the HWB that has received little attention so far was transected by two forest stewards (Luke and Drexie) in October. We started at the Two Cedars area (about 150 feet down the main trail) and crossed the HWB just west of a line of old Alnus rubra (red alder).
    • North of the stream, we saw a large number of small Vaccinium parvifolium (red huckleberry). It was unclear whether they were planted or volunteers.
    • Immediately south of the stream crossing the soil was very wet and marshy. There were many large Lysichiton americanum (skunk cabbage) leaves dying back. There was also evidence of Equisetum arvense (horsetail) from earlier in the season.
    • Further south of the stream crossing, the ground rose slightly and was dryer. At that point, the Rubus spectabilis (salmonberry) became very thick.
    • There was some Polystichum munitum (sword fern) and Athyrium filix femina (lady fern), but ground cover in general was relatively sparse.
    • There was a thicket of Ribes bracteosum (stink currant) at the border of the wet and dry areas.
    • At the base of the south slope we stopped to write down what we’d seen so far. In addition to the already mentioned plants, there were:
      • Emergent (that is, taller than the shrub layer) Acer macrophyllum (big leaf maple) and Alnus rubra (red alder).
      • Sambucus racemosa ssp. pubens (red elderberry) thicket.
      • Sorbus aucuparia, European ash.
      • An apparently dead Populus balsamifera (cottonwood) stake from 2012.
    • Going up the south slope to the houses, we saw:
      • Sword fern as dominant groundcover.
      • Occasional salmonberry, but fairly isolated and lower on the slope. Otherwise, no shrub layer to speak of.
      • Big leaf maple trees dominant towards the middle of the slope, with conifers along the rim (we weren’t able to identify the conifers from that distance).
    • We continued east along the base of the south slope towards the 24th Ave. Slope.
      • Outside of the tree cover, the ivy was very dense, bushy, and had many many seed pods.
      • There were a couple small Thuja plicata (Western red-cedar) that Tad and Luke had liberated from salmonberry in 2012; Luke and Drexie liberated them again.
      • The base of the 24th Ave. rim was dominated by Hedera helix (English ivy), with Urtica dioica (stinging nettle) growing up between it. There was no shrub layer and no regenerating trees.
      • The culvert that empties into the park from the corner of the 24th Ave. slope and the south slope has gouged a deep channel. There is a lot of construction rubble in the channel, but also some large garbage (garbage cans, tires, etc.) that should be removed. This is on private property, but if at all possible it should get treated with some rip rap. The channel is still carved farther down, and at the base of the slope and in the flat area it can receive fascines or woody debris.
  4. For 2015, we will work with the Parks Department to determine what can be the scope of volunteer work in the private property areas of the HWB, and then contact the neighbors to get permission for that work.

Wetlands: Central Valley

The Central Valley is the area in light green (planting) and pale yellow. The blue line is the stream. (Source: GSP Reference Map on ArcGIS.com.)

The Central Valley is the area in light green (planting) and pale yellow. The blue line is the stream. (Source: GSP Reference Map on ArcGIS.com.)

At 1.97 acres, the Central Valley (“CV”) is the largest HMU in North Beach Park. Its northern border is a stream crossing; its eastern border is the main social trail; its southeastern border is a stream crossing and the start of the south loop social trail; its western border is the south loop social trail. The gradient between the eastern side of the central valley and the main social trail varies from almost nothing to very steep. The gradient between the south loop social trail and the floor of the valley is very steep throughout.

The slopes of the valley are heavily invaded, but explorations of the middle of the valley reveal an area not in such bad shape. The Rubus spectabilis (salmonberry; RUSP) layer of the canopy is so dense that it makes exploration very difficult. In the summer of 2014, we did a belt transect through the widest part of the CV; please see “Vegetation” below for a discussion of the results of the transect, and “Belt Transect” in “Monitoring” for a discussion of the protocol.

The tree canopy percent cover for the CV is 60% deciduous, almost exclusively Alnus rubra (Red alder). There is less than 1% coniferous cover, Thuja plicata (Western red-cedar), located in the southwest corner. There is about 5% cover of regenerating deciduous trees, and less than 1% of regenerating coniferous trees. The CV has the largest canopy gaps in the park, allowing Calystegia sepium (bindweed) to establish in the sunlight.

The reference ecosystem and target forest type for the CV are the same as for the Headwaters Bowl: “riparian forest and shrubland” for the ecosystem and ALRU/RUSP/CAOB-LYAM (Red alder/salmonberry/slough sedge – skunk cabbage) (Chappell 2006) for the target forest type.

The existing plant community is ALRU/RUSP (Kunze), and the soil is correspondingly relatively dry. The saturated areas of the CV are much smaller than those in the Headwaters Bowl.

The RUSP layer is so dense that it forms a closed canopy and prevents any other shrubs or trees from establishing. The most noticeable groundcover under the RUSP canopy is Tolmiea menziesii (Piggyback) and Hedera helix (ivy). Care must be taken during restoration not to disrupt the RUSP canopy lest the ivy take off.

The southeastern section of the CV (part of Subarea A, below) is in phase one of restoration, invasive removal. See “Monitoring Protocols and Success Metrics.”

As with the Headwaters Bowl, the CV is split into four sub areas, depending on who can do the work or the technique for best restoration. See “Invasive Removal and Vegetation Plan,” below.

Water Flow

Again, as with the Headwaters Bowl, most of the water flow in the Central Valley is from the southern wall of the park towards the stream channel. The water appears to be more channelized than in the HWB; perhaps this is because the RUSP canopy provides greater soil control.

Vegetation

1/10th Acre circular monitoring plot

There was one 1/10th acre circular forest monitoring plot established in the south eastern corner of the Central Valley (Subarea B). Please see “Green City Monitoring Protocol” in “Monitoring Protocols” for a discussion of this protocol. The baseline monitoring was taken in September 2011, and the plot was revisited in August 2012. As with the HWB plot (above), percent cover was determined by consensus of the people doing the surveying, and reported in broad categories for city-wide consistency.

2011 invasive groundcover for Central Valley monitoring plot.

2011 invasive groundcover for Central Valley monitoring plot.

2012 invasive cover in Central Valley monitoring plot.

2012 invasive cover in Central Valley monitoring plot.


Key: Groundlayer and shrub percentages are for percent cover. Tree density is trees per acre. Red bar indicates immediate attention needed; light orange bar means attention needed soon. Source: EarthCorps, 2011 and 2012.

The figures below compare native groundlayer change between 2011 and 2012. Note in particular the return of Hydrophyllum tenuipes (Pacific water leaf) and Lysichiton americanum (skunk cabbage) both of which returned from the seed bank.

2011 native groundcover in the Central Valley monitoring plot.

2011 native groundcover in the Central Valley monitoring plot.

2012 native groundlayer cover in the Central Valley monitoring plot.

2012 native groundlayer cover in the Central Valley monitoring plot.

Belt transect

In the summer of 2014, a cross-gradient belt transect was done in North Beach Park that crossed the Central Valley along the 90th St. right of way. Eight 4’x16’ plots were established in the Central Valley. The transect went from west to east, through subareas C, D, and A.

The following table lists the target forest type species for the Central Valley, all the species found in the belt transect, their percent cover across the entire transect, and what the percent cover of their TFT goal is. Percent cover was determined by one person consistently, and is given in specific amounts. Please see the key below the table for a full explanation of the numbers.

Scientific Name Common Name Pct. Cover TFT Goal
Acer circinatum Vine maple 0.00 4.00
Acer macrophyllum Big leaf maple 26.11  
Alnus rubra Red alder 32.22 93.00
Angelica genuflexa Kneeling angelica 0.00 20.00
Athyrium filix-femina Lady fern 2.44 4.00
Atrichum selwynii Crane’s-bill moss 0.33  
Calystegia sepium false bindweed 0.33 0.00
Carex amplifolia Bigleaf sedge 0.89  
Chrysosplenium glechomifolium Pacific golden saxifrage 0.00 15.00
Circaea alpina Enchanter’s nightshade 0.00 3.00
Dryopteris expansa Spiny wood fern 0.22  
Equisetum telmateia Giant horsetail 2.22  
Erhythranthe guttata Yellow monkey-flower 0.00 4.00
Hedera helix English Ivy 14.28 0.00
Hydrophyllum tenuipes Pacific waterleaf 3.33  
Ilex aquifolium Holly 3.00 0.00
Lysichiton americanum Skunk cabbage 5.22 30.00
Moss   0.44 20.00
Mycelis muralis Wall lettuce 0.06 0.00
Oenanthe sarmentosa Water parsley 0.67 6.00
Oxalis oregana Oregon oxalis 0.00 8.00
Picea sitchensis Sitka spruce 0.00 8.00
Poa trivialis Rough-stalk bluegrass 0.00 30.00
Polystichum munitum Sword fern 3.06 6.00
Prunus laurocerasus Cherry laurel 0.39 0.00
Ranunculus repens Creeping buttercup 0.33 0.00
Ribes bracteosum Stink currant 0.11  
Rubus armeniacus Himalayan blackberry 0.67 0.00
Rubus spectabilis Salmonberry 53.89 57.00
Sambucus racemosa Red elderberry 0.44  
Stachys chamissonis var. cooleyae Coastal hedgenettle 0.00 4.00
Stachys mexicana Mexican hedge-nettle 0.00 4.00
Tolmiea menziesii Piggyback 2.17 34.00
Urtica dioica Stinging nettle 2.72

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.

Plots 4 through 10 of the transect were on the floor of the Central Valley. The following chart illustrates the relationship between density of salmonberry and red alder cover and ivy. How this will affect restoration is discussed in “Subarea D,” below.

Interaction of Salmonberry, Red alder, and English ivy.

Interaction of Salmonberry, Red alder, and English ivy.

Invasive Removal and Restoration Plan

There are four distinct subareas to the Central Valley.

North is to the top. A: All volunteers can work here. B: Forest stewards and experienced volunteers. C: Parks District Natural Area Crew (slope). D: Forest stewards and experienced volunteers.

North is to the top. A: All volunteers can work here. B: Forest stewards and experienced volunteers. C: Parks District Natural Area Crew (slope). D: Forest stewards and experienced volunteers.

Subarea A

Subarea A (outlined in blue above) measures approximately 17,350 square feet. It lies between the social trail and the stream and is relatively flat and accessible. A holly thicket was cleared from the southeastern portion in 2011. The ground returned with Hydrophyllum tenuipes (Pacific waterleaf) and was replanted with shrubs and ferns in the subsequent planting seasons.

The dark green section of Subarea A (approximately 9,600 square feet) was cleared and planted by EarthCorps volunteers in 2013. This work will be extended and monitored by the Friends of North Beach Park. In January 2014, Friends of North Beach Park cleared about 800 square feet of black berry past the north end of the dark green section of Subarea A. This received some Deschampsia cespitosa (Tufted hair grass) and Fraxinus latifolia (Oregon ash) in March that has established well. Ribes bracteosum (Stink currant) is spreading into the cleared area from nearby. The clearing did not reach the streambank because the ground was still very wet.

Work in Subarea A can be done by any volunteers or forest stewards. Parks Department Natural Area Crew will be requested for large laurel and holly removal.

Care must be taken working close to the stream to not disrupt the streambank. A section of Subarea A lies across the trail from an area called Knotweed Hill. This area should receive extra attention and monitoring.

Suggested tasks for Subarea A:

  • Plant newly cleared area in Fall of 2013.
  • Work with Parks Department crews to eradicate the holly and laurel.
  • Monitor invasive resurgence and native establishment in the Earthcorps-cleared areas.
  • Connect the cleared areas.

Subarea B

Subarea B, outlined in red above, measures approximately 4,800 square feet. It is a large, active seep with water flowing from the south wall of the ravine. The soils are permanently saturated and can bear little or no walking. The ground is too wet for all but such obligate plants as Oenanthe sarmentosa (Water parsley) and H. tenuipes.
This seep is bordered by a social trail, the soil compaction of which provides a little stability. There are also three large Acer macrophyllum (Big leaf maple), two of which are visible below, taken before any restoration work was done.

Central Valley Subarea B in 2011.

Central Valley Subarea B in 2011.

There is a large conifer nurse log (obscured in the photo above) lying across the seep that provides some stability. Tsuga heterophylla (Hemlock) trees have been planted into the nurse log and are doing well.

Hedera helix (English ivy) grows down from the slope, under the trail, and then over the seep. The ivy is not firmly rooted in the seep and provides little or no stability or erosion control. However, clearing the ivy would destabilize the sides of the seep and disrupt the trail.

In November, 2013, some planting was done in Subarea B. They are listed in the table below.

Scientific Name Common Name #
Alnus rubra Red alder 1
Carex deweyana Dewey sedge 6
Carex obnupta Slough sedge 4
Cornus stolonifera Redtwig dogwood 6
Juncus acuminatus Tapertip rush 6
Picea sitchensis Sitka spruce 1
Physocarpus capitatus Pacific ninebark 4
Salix lucida Pacific willow 4
Scirpus microcarpus Panicled bulrush 2

The C. stolonifera were livestakes. All others were potted.

These were installed in two locations in Subarea B. In both cases, only the minimum amount of clearing was done to allow planting. As of summer 2014, all the plants appear to be doing well. We’ve also spread seed berries from Lysichiton americanum (skunk cabbage) into bare areas.

Suggested tasks for Subarea B:

  • Plant shrubs in areas of stable soil, at the base of the slope and around the trees and nurse log.
  • As these establish, spread planting into less stable areas.
  • When the shrub layer establishes, remove ivy from beneath it and increase groundcover diversity.

For further plans for Subarea B, please see “Stewardship Grant,” below.

The ivy comes down to Subarea B from the West and South Slopes. For a discussion of the plans for those HMUs, please see the “Uplands and Slopes” chapter.

Subarea C

Subarea C, outlined in green above, is the least volunteer-accessible area of the Central Valley. It measures approximately 26,490 square feet. The western border is the south loop social trail, and the eastern border is on the floor of the valley. The social trail is frequently 50 and more feet above the floor of the valley, with well over 40% grade. Work here will have to be done by contract or natural area crew, either arranged through Green Seattle Partnership or secured through a grant.

Subarea C is heavily invaded by Rubus armeniacus (Blackberry), Calystegia sepium (Bindweed), and many other ornamental and invasive plants. The true extent of the invasiveness, or what remnants of native plant cover under the blackberry or bindweed, is not known at this time.

Subarea D

Subarea D, at approximately 38,970 square feet (yellow outline above), is the largest area of the Central Valley. The belt transect cut across it at the widest point, but the rest of Subarea D has not been fully explored.

As discussed in “Vegetation,” above, the dense salmonberry and red alder canopy might be controlling the ivy and other invasives – at the cost of preventing tree succession or shrub and groundcover diversity. Care must be taken not to disrupt the salmonberry layer, as this would allow the ivy to take off, and perhaps choke out restoration plantings.

We plan to remove the ivy from underneath the salmonberry in test sections beginning in early spring 2015, before the salmonberry and red alder are fully leafed out. This will allow the sun to reach the soil and promote any seedbank or native growth resurgence. In the summer, we’ll spread seeds from piggyback and other plants already growing in Subarea D. Live stakes from other shrubs growing in the park will be introduced as well, drawing from a number of different plants to avoid problems caused by dense cloning. Deep-shade groundcover will be planted or spread by seed.

As diversity increases, we will remove more ivy and thin the salmonberry to start tree succession. We’ll begin with Alnus rubra. Although this is already the dominant tree cover, it is mainly large, old trees, with no seedlings or sub-canopy examples yet seen. As the next generation of A. rubra establishes, we will begin planting Thuja plicata (Western red-cedar) and Tsuga heterophylla (Western hemlock).

This is a modification of the Bradley method (Bradley, 1988). Although it might sound like it would take longer than the general clearing and replanting, it will have less disruptive impact on existing habitat and aquatic systems (Apastol & Berg, 2006)

Suggested tasks for Subarea D:

  • Remove ivy from under Rubus spectabilis before leaf out
  • Monitor for native plant return from seedbank
  • After seed set, spread seeds from plants already growing under the salmonberry (mostly Tolmeia menziesii [piggyback]).
  • Live stake with stakes taken from other shrubs in the park, particularly Sambucus racemosa (Red elderberry) and Rubus parviflorus (Thimbleberry).
  • In the fall, spread seeds of plants that like deep shade under the salmonberry.
  • When an alder falls, take advantage of the extra light to encourage conifer succession.

All tasks are to be done with as little disturbance to the salmonberry cover as possible.

October Work Party Report

The October work party for Friends of North Beach Park was, once again, a tremendous success. The weather cooperated: it was raining in the morning, but during the work party itself, there were even occasional sunbreaks. It didn’t start raining again until we were safely back home.

We were joined this time by about eleven volunteers from the North Seattle College iCARE program. The students worked hard and well and with the guidance of the forest stewards, we got 450 plants into the ground, which were:

The list

Those are all wetland obligate (they have to live in a wetland) or facultative wetland plants (they prefer wetland environments, but about a third of the time they can be found in drier spots). The Carex amplifolia and Glyceria elata have been seen growing in isolated patches in North Beach Park, but the C. stipata has not been seen in the park at all. The other three have been planted during restoration in small quantities. None of the plants have been seen growing or have been planted near where they were planted Saturday, which will make monitoring of the project in the spring and summer easy.

Julie sorted them into five buckets, 10 or 20 per bucket.

Sorting

The five buckets were to correspond with five areas for receiving the plants. All the plants got put in where they were intended, and we had some extras to spread around.

Working in a seep

Above, we see Loren (bareheaded, in black jacket to the left) and Drexie (kneeling in purple jacket to the right) leading a group of the North Seattle students in planting. They’re working in a seep that wasn’t in the original planting plan, but I was really glad to see get something put into it.

Duckboards

The photo above shows Doug leading other students in planting. They’re standing on “duckboards,” a technical term for sheets of plywood (in this case, just particle board) that you can pick up and move around to avoid churning up the soil of a wetland and breaking the structure. The leaf-fall makes it a little less obvious, but the area they’re about to work in is bare soil, the result of a new shift in the water flow.

Everything went smoothly enough that we were actually done early. Here’s the group picture:

The victorioous crew!

Doug had gone back into the park to plant one straggler. In the back we see Morry on the left, with Drexie, Loren, and Tad in the back center. Julie is kneeling in the front. Everyone else is from North Seattle.

These plants were purchased as partial fulfillment of a stewardship grant from the Central Puget Sound chapter of the Washington Native Plant Society. As I said above, these are all plants that are under-represented in North Beach Park or have not yet been observed growing there. Planting them in such great quantities will greatly increase the ecological diversity of North Beach Park at the herbaceous level, and will help stabilize the seeps against erosion.

As usual, there are a few more pictures on Flickr. And there are even some pictures on Facebook, posted by the iCare coordinator.

Wetlands: Introduction and Headwaters Bowl

This post gives an overview of the wetlands in North Beach Park and looks specifically at the Headwaters Bowl. The next post looks at the Central Valley. The third post in this series will discuss the stewardship grant from the Washington Native Plant Society to the Friends of North Beach Park. The 92nd St. Wetlands will be discussed later, with Fletcher’s Slope.

Approximately 4.5 acres of North Beach Park are designated as wetlands. These wetlands are formed by broad, horizontal, groundwater seeps emerging from the sides of the ravine. These join to form the stream that leaves the park. The seeps are perennial, and have lasted through record droughts.

The wetlands have many areas that are permanently saturated, and walking in them quickly disrupts whatever soil structure there is. Other places are more stable.

Figure 1: Wetlands in North Beach Park. Thick green lines indicate park boundaries. Light grey lines indicate HMU boundaries. The filled blue area are the wetlands. Wetland delineation by Doug Gresham of Gresham Environmental (2012). (Map by the author.)

Figure 1: Wetlands in North Beach Park. Thick green lines indicate park boundaries. Light grey lines indicate HMU boundaries. The filled blue area is the wetlands. Wetland delineation by Doug Gresham of Gresham Environmental (2012). (Map by the author.)

Doug Gresham, of Gresham Environmental, delineated and typed the wetlands in 2012:

North Beach has both Palustrine (freshwater) and Riverine (riparian) wetlands. The plant community is scrub/shrub and the water regime ranges from saturated soil to permanently flowing streams. The groundwater seep wetlands would be called palustrine, scrub/shrub, saturated (PSSc). The stream would be called riverine, upper perennial, unconsolidated shore, permanently flooded (R3USh).

The hydrogeomorphic classification system groups wetlands based on functions and values. … The groundwater seep wetlands would be called slope wetlands and the stream is a riverine wetland.

The Washington Department of Ecology classifies wetlands into four categories based on their hydrogeomorphic class and score from a rating form. King County and City of Seattle governments rely on this classification system to create their critical area ordinances. The highest quality wetlands (Category I) are rare, while low quality wetlands (Category IV) are somewhat rare also. Most wetlands fall into the Category II and III level depending on how well they function. North Beach would probably be Category III because it is degraded. (Gresham, 2014)

In October 2005, the US Fish and Wildlife Service did a fish habitat survey of streams in the Seattle area. “Unnamed PS08 West Fork” is the stream that flows through North Beach Park (see figure 2, below). At their sample site (which would now be in the Headwaters Bowl HMU), they found the stream to have a mean wetted width of 1 meter (m); a mean depth of 0.03m with a max depth of 0.1m; and to consist of 100% riffles with no pools or glides. The substrate was 100% silt/sand. They did not catch any fish in the sample site. (Tabor 2010)

Figure 2: Location of US Fish and Wildlife 2005 survey sample in North Beach Park.

Figure 2: Location of US Fish and Wildlife 2005 survey sample in North Beach Park.

The Central Valley, at 1.97 acres, and the Headwaters Bowl, at 1.39 acres, are the two largest HMUs in North Beach Park. For restoration purposes, we have split them into four subareas each. The subdivision is based on who can do the work: all volunteers, experienced forest stewards, Parks Department Natural Area Crew, or privately-contracted restoration crew.

Headwaters’ Bowl

Description

Figure 3: Headwaters Bowl. The Headwaters Bowl is the area in light green (planting) and blue (establishment). The blue line is the stream. North is to the top.

Figure 3: Headwaters Bowl. The Headwaters Bowl is the area in light green (planting) and blue (establishment). The blue line is the stream. North is to the top. (Source: GSP Reference Map on ArcGIS.com.)

The Headwaters Bowl (“HWB”) is the easternmost HMU of North Beach Park.

The northern boundary is the main trail of the park, the eastern boundary is 24th Ave. NW, the southern boundary is property lines and the South Slope, and the western boundary is the stream crossing and the social trail between the Headwaters Bowl and the Central Valley.

The property lines cut the bottom of the bowl and the 24th Ave. slope in half, and remove the southern slope entirely. Parks Department volunteers and Natural Area Crew are not allowed to work on private property. This complicates restoration of the HWB as discussed below in “Invasive Removal and Restoration Plan.”

At the start of restoration, nearly half the trees in the HWB had severe Hedera helix (ivy) infestations which frequently reached into the canopy. There were large pockets of ivy monoculture on the ground.

The percent cover for trees was approximately 70% deciduous, with Alnus rubra in the wetlands and Acer macrophyllum on the dryer slopes and uplands. There was 5-10% conifer cover, exclusively Thuja plicata (Western red-cedar). The remaining 15-20% cover was open gaps, either over areas too wet to sustain trees or where A. rubra had fallen. The percent cover of the regenerative trees (tall enough to be above the shrub layer) was less than 5% for deciduous and less than 1% for coniferous trees.

Ilex aquifolium (English holly) and Prunus laurocerasus (English laurel) formed occasional dense thickets. Most of these have been removed, either by uprooting or cutting and painting with herbicide.

The HWB native plant communities at the start of restoration were very similar to the Alnus rubra/Rubus spectabilis (Red alder/Salmonberry; ALRU/RUSP) and Alnus rubra/Lysichitum americanum (Red alder/skunk cabbage; ALRU/LYAM) communities described by Kunze (1994). The differences were largely that the communities in the park lacked herbaceous diversity compared to the reference communities.

These communities are dominated by an Alnus rubra (red alder) canopy, with either Rubus spectabilis (salmonberry) or Lysichitum americanum (skunk cabbage) as the undercanopy. Kunze describes the ALRU/LYAM community as being wetter than ALRU/RUSP, and that is the case in NBP. (Plant communities are discussed in more detail in “Target Forest Types”).

There is a canopy gap over the most saturated, eastern part of the HWB. This area is dominated by skunk cabbage and horsetail, with some Salix sitchensis (Sitka willow) shrub. The invasive plants here include Rubus armeniacus (blackberry) and Calystegia sepium (bindweed). Numerous A. rubra lean over this part of the HWB from the slopes. As they die and fall, the gap will enlarge. This will also increase the amount of coarse woody debris in the wetland and the number of rootballs on the slope walls.

Progressing to the west, the topography and soils become more complicated. Some areas are more stable, and some are seeps that have reached down to the gleyed soils. As the ravine narrows, Acer macrophyllum (Big leaf maple) on the south slope add their shade.

The majority of the HWB is in phase two, “planting,” of restoration. A section of Subarea C is considered to be in “establishment,” phase 3. For a discussion of the phases, please see “Monitoring Protocols and Success Metrics.”

Water Flow

Groundwater emerges from several places at the base of the 24th Ave. slope. One of these areas has a number of displaced conduits. During heavy rainfall, water emerges from a conduit in the southeastern corner of the hillside.

Through the rest of the Headwaters Bowl, the water emerges as seeps or occasionally channels from the south slope of the ravine. In many places the seeps have carried away most of the soils.

These seeps join the stream, which runs along the northern edge of the headwaters bowl. Water flow in North Beach Park, in general, needs a lot more research and observation.

Vegetation

As discussed above, the plant communities in the HWB are currently a mixture of ALRU/LYAM (to the east) and ALRU/RUSP (to the west).

The reference ecosystem for the Headwaters Bowl is “riparian forest and shrubland.” The target forest type is ALRU/RUSP/CAOB-LYAM (Red alder/salmonberry/slough sedge – skunk cabbage) as described by Chappell (2006).

There has been one circular, 1/10th-acre, monitoring plot established in the Headwaters Bowl. Baseline monitoring was taken in August 2012, with a follow-up in August 2013. See “Green City Monitoring Protocol” in “Monitoring” for a discussion of this protocol. This monitoring plot was established in the middle of the most saturated section of the Headwaters Bowl.
The following table presents the vegetation findings from the 2012 and the 2013 monitoring and the change. Native plants listed as 0 in the “2012 % Cover” column were planted in autumn 2012. Percent cover was determined by consensus of the people doing the monitoring plot, and is reported in broad categories to enable the data to be consistent across the city.

Table 1: Forest Monitoring Plot report, Headwaters Bowl.

Scientific Name Common Name 2012 % Cover 2013 % Cover Change
Athyrium filix-femina Lady fern 1-5% 1-5% None
Cardamine hirsuta Shotweed 0 <1% Increase
Carex obnupta Slough sedge 0 <1% Increase
Convulvus arvensis Field bindweed <1% 6-15% Increase
Crataegus douglasii Black hawthorne 0 <1% Increase
Epilobium ciliatum Willowherb <1% <1% None
Equisetum arvense Horsetail 26-50% 26-50% None
Fraxinus latifolia Oregon ash 0 <1% Increase
Glyceria elata Tall mannagrass <1% <1% None
Hedera helix English Ivy 26-50% 26-50% None
Lonicera ciliosa Orange honeysuckle 1-5% 1-5% None
Lysichiton americanum Skunk cabbage 1-5% 6-15% Increase
Malus fusca Pacific crab apple 0 <1% Increase
Oenanthe sarmentosa Water parsley <1% <1% None
Polystichum munitum Sword fern <1% <1% None
Ranunculus repens Creeping buttercup 6-15% 6-15% None
Rubus armeniacus Himalayan blackberry 26-50% 16-25% Decrease
Rubus spectabilis Salmonberry 26-50% 26-50% None
Rumex crispis Curly dock <1% <1% None
Salix sitchensis Sitka willow 1-5% 1-5% None
Scirpus microcarpus Small-fruited bulrush 0 <1% Increase
Solanum dulcamara Bittersweet nightshade <1% <1% None
Spiraea douglasii Hard hack 0 <1% Increase

Only one invasive plant decreased in cover, Rubus armeniacus (blackberry). This was the plant we most vigorously removed. The native plants that went from 0 to <1% cover had been planted in the fall of 2012. Lysichiton americanum (Skunk cabbage) increased from the seed bank. Calystegia sepium increased noticeably all over the park in 2013.

Although this gives a good representation of the most-saturated areas of the HWB, it does not give a good representation of the HWB as a whole. A couple dozen feet to the west of this monitoring plot, there is a stand of A. rubra that indicates dryer conditions. This allows greater shrub establishment.

Invasive Removal and Restoration Plan

I have divided the Headwaters Bowl into four subareas, based on who can perform the needed restoration work (see below).

Figure 4: Headwaters Bowl and subareas. A: All volunteers can work here. B: Forest stewards and experienced volunteers. C: Parks District Natural Area Crew (slope). D: Privately contracted crew (slope, private property).

Figure 4: Headwaters Bowl and subareas. A: All volunteers can work here. B: Forest stewards and experienced volunteers. C: Parks District Natural Area Crew (slope). D: Privately contracted crew (slope, private property).

Subarea A

Subarea A is between the main trail and the stream bank. It is relatively flat and dry, making it accessible to all volunteers. It measures approximately 16,500 square feet (all areas calculated using the measurement tool on GSP Reference Map on Arcgis.com).

Subarea A has received the most attention of any area in the park, beginning with the very first work party. As a consequence of it receiving such early attention, no good record was kept of its pre-restoration state; the notes below are reconstructed from memory.

There were few areas of Hedera helix (English ivy) monocultures in Subarea A. There were some areas of Ilex aquifolium (English holly) and Prunus laurocerasus (Cherry laurel) dominance. The ivy has been removed by hand. The holly was removed by uprooting. The laurel was removed by cutting and painting.

In late summer and fall of 2013, several EarthCorps work parties concentrated on invasive removal in this section.
Plants have been installed and invasives removed every year, and it is now in an establishment phase.

Suggested tasks for Subarea A:

  • Explore the western end in further detail.
  • Continue monitoring the planted area for native plant establishment and invasive resurgence.
  • Track mature Alnus rubra and naturally regenerating Thuja plicata and Acer macrophyllum.
  • Start a new generation of deciduous trees.
  • Add to the herbaceous diversity annually.
  • In 2021 (ten years after restoration began), add a new generation of conifer trees.

Subarea B

Subarea B is the center of the bowl, and because of the saturation and fragile soil structure is more difficult to work in than Subarea A. This makes it accessible to small groups of experienced forest stewards only. It measures about 45,000 square feet.

The widest part, to the right in the image, is permanently saturated. It receives invasive removal in the late summer, when it’s relatively dry. It has received plantings of graminoids and shrubs. The eastern edge of Subarea B is the location of the circle monitoring plot discussed above. The part of Subarea B not in park property needs further exploration.

The narrower part has many seeps, separated by tongues of soil held in place by Carex obnupta (slough sedge) and/or Rubus spectabilis (salmonberry). In the spring and summer, these seeps contain forbs such as Oenanthe sarmentosa (Water parsley). However, there is no woody vegetation to hold the seeps during winter.

Some Picea sitchensis (Sitka spruce) and Thuja plicata (Western red-cedar) have been planted in the seeps.

In June 2014, Friends of North Beach Park received a $500 stewardship grant from the Puget Sound Chapter for the purchase of wetland plants. These plants will be installed along the streambank and in the seeps of the western (left) edge of Subarea B of the Headwaters Bowl, and across to Subarea B of the Central Valley. This grant is discussed in more detail in “Stewardship Grant.”

Suggested tasks for Subarea B, in the lobed area to the east:

  • Continue removing blackberry.
  • Establish shrubs where possible, graminoids elsewhere.
  • Explore the base of the slope and the bowl during a rain event.

Suggested tasks for Subarea B, in the narrow part to the west:

  • Implement the WNPS Stewardship Grant in autumn of 2014.
  • Continue removing invasives as necessary.
  • Monitor seeps for erosion.
  • Establish obligate wetland plants in the seeps.

Subarea C

Subarea C measures roughly 10,200 square feet. It is the slope along 24th Ave NW and around the entrance to the park along the main trail. Because it is a greater than 40% grade, only Parks Department Natural Area crew or contract crew can work on it. Volunteers have worked on it in the past, however.

In 2011, trees along the rim and slope received survival rings and there was some clearing of the slope.

In 2012 and 2013, the rim received some planting by the Friends of North Beach Park. During the summer months, these plants are watered and weeded. These plants include shrubs such as Aruncus dioicus var. acuminatus (Goatsbeard), Rosa nootkana (Nootka rose) and trees such as Pseudotsuga menziesii (Douglas-fir) and Pinus contorta var. contorta (Shore pine).

In 2013, the slope was partially cleared by a group of EarthCorps volunteers. The clearing was completed by a contract crew, who also put down jute rolls and planted in the fall.

Figure 5: Steep slope jute erosion control by contract crew.

Figure 5: Steep slope jute erosion control by contract crew.

The remainder of the clearing, following the curve of the slope along 24th Ave. and ending at the property line, will happen in 2014 or 2015.

Volunteers and forest stewards can maintain the plants at the rim and the base, but further tasks along the slope in this subarea will be executed by the Parks Department.

Subarea D

Subarea D measures approximately 13,800 square feet. It has not been explored in any great depth. Some trees were given survival rings during the first work parties in 2011. One house appears to have impermeable erosion control fabric, held down by sandbags, on the slope beneath it.

Subarea D is entirely private property on a very steep slope. The houses were built between 1959 and 1963 (King County Parcel Viewer), long before there was any movement to make the ravine a park or any attempt to preserve urban wetlands. The property lines, as shown below, extend into the bowl of the park, which allows the owners to have addresses on 24th Ave. This group of houses, as a whole, is called Olympic Terrace.

Figure 6: Property lines and park boundaries of HWB. The green area is North Beach Park. The red lines are parcel boundaries for private property. (Source: Seattle Department of Public Development DPDGIS).

Figure 6: Property lines and park boundaries of HWB. The green area is North Beach Park. The red lines are parcel boundaries for private property. (Source: Seattle Department of Public Development DPDGIS).

Due to the steepness of the slope, and the fact that it is private property, Subarea D can only be worked on by a privately contracted crew.

Working in Subarea D depends on securing the cooperation of the homeowners. We plan to contact them in autumn 2014 or early 2015 by doorbelling or leaving door hangers. If this contact is successful, we will

  • Explore the area along the bowl and the base of the slope to get an estimate of its invasiveness and what work needs to be done.
  • Design restoration plans that range from one-year brute force through multi-year phased work (which plan gets executed would depend on the size and time span of the grant).
  • Work with neighbors to write a grant that can be applied to private property (with King Conservation District or other organization).
  • Restore Subarea D per grant.

The large contingencies in this plan are (a) successfully contacting and securing the cooperation of the neighbors and (b) obtaining the very competitive King Conservation District grants.

The constraints against working in Subarea D would make it low priority if it were in another section of the park. However, its proximity to the headwaters increases its importance.

Planting Season!

Planting season has hit the Pacific Northwest, and restoration projects all over the place are getting their shovels dirty. No less is happening in North Beach Park — we have planting parties planned for the next FOUR work parties, October, November, January, and February!

October
The October work party happens Saturday, October 25, from 9 a.m. to noon. Please sign up here. The Friends of North Beach Park will be joined by international students from North Seattle College, volunteering with their I-CARE program.

October features wetland graminoids (grasses) and one forb. These plants will come from 4th Corner Nursery in Bellingham, and are purchased with monies from a stewardship grant from the Central Puget Sound Chapter of the Washington Native Plant Society. We also appreciate the support of our fiscal sponsor, Seattle Parks Foundation, for processing the money.

These will be planted in the Headwaters Bowl and Central Valley habitat management units of North Beach Park.

Scientific Name Common name Size Form Number
Carex amplifolia Broad-leaved sedge br Gr 50
Carex stipata Sawbeak sedge br Gr 100
Deschampsia caespitosa Tufted hair-grass br Gr 50
Glyceria elata Tall mannagrass br Gr 100
Juncus ensifolius Daggerleaf rush br Gr 50
Scirpus microcarpus Panicled bulrush br Gr 100
Veronica americana American brooklime br Fo 100

Although this is 550 plants, they’re all pretty small.

November
The November work party will happen on Saturday, the 22nd. Build up that appetite and enjoy your Thanksgiving feast that little bit more, because you’ve done some good for Seattle parks! Sign up here. Friends of North Beach Park will be joined again by international students from the North Seattle College I-CARE program.

November will see more plants installed in the main body of North Beach Park. These plants are provided by Green Seattle Partnership. There will be one tree, one shrub, and two grasses and two forbs.

Scientific Name Common name Size Form Number
Acer macrophyllum bigleaf maple 1 gal Tr 6
Asarum caudatum wild ginger 1 gal Fo 20
Oplopanax horridus Devil’s club 1 gal Sh 10
Petasites frigidus coltsfoot 1 gal Fo 20
Scirpus acutus hardstem bulrush 1 gal Gr 8
Scirpus microcarpus panicled bulrush 1 gal Gr 8

For the first three years of restoration, we planted hundreds of conifer trees in North Beach Park. Now we’re going to switch gears for a while: Let the new conifers establish and get well-situated for the next three to five years, and do some replacement of the deciduous canopy.

We skip December, because the 4th Saturday falls between Christmas and New Year’s Eve. We hope you have a good holiday.

January
In January, we return to the South Plateau to plant the last of the plants provided by Green Seattle Partnership. The entrance to the South Plateau is at NW 88th St. and 27th Ave. NW. The January work party will happen on Saturday, the 24th. The event is not posted to Cedar yet, but it will have full directions and information. We DO know what we will be planting, though.

Scientific Name Common name Size Form Number
Holodiscus discolor oceanspray 1 gal Sh 11
Lonicera involucrata twinberry 1 gal Sh 7
Mahonia nervosa dwarf Oregon grape 1 gal Sh 25
Malus fusca Pacific crabapple 1 gal Tr 5
Polystichum munitum sword fern 1 gal Fe 25
Pseudotsuga menziesii Douglas fir 1 gal Tr 5
Rosa gymnocarpa bald-hip rose 1 gal Sh 25
Rosa nutkana Nootka rose 1 gal Sh 25

February
This will be our last planting work party for the 2014-2015 planting season. Well, that we’re planning on as we write (four months in advance). Who knows what the future portends?

This work party will feature shrubs and small trees, the second half of the stewardship grant purchase from the Washington Native Plant Society.

Scientific Name Common name Size Form Number
Fraxinus latifolia Oregon ash 6-12″ br Tr 50
Malus fusca Pacific Crab Apple 3-6″ br Tr 50
Physocarpus capitatus Pacific ninebark 6-12″ br Sh 50
Salix lucida Pacific willow 6-12″ br Tr 50
Salix sitchensis Sitka Willow 6-12″ br Tr 100

The February work party will be back in the main body of the park, and will happen on the 28th. As soon as the information gets posted to Cedar, we’ll link to it on Nature Intrudes.

We also plan to do a little experiment: Hold back some of the plants of each species, and keep them in a well-tended nursery for a year or two. The question is: Will the plants that get the extra attention have a better survival rate than the plants installed immediately?

That’s a little over a thousand plants altogether. Most of them are going into wetter areas of the park, which means they should make it through the summer drought fairly well.

Success Metrics

Tree-iage Grid

At the start of restoration, each HMU in a park is evaluated according to a 9-square “tree-iage” grid, rating from high composition/low threat to high threat/low composition. This helps GSP estimate how much time and effort the restoration will take. See below.

Forterra "Tree-iage" grid. Source: GSP Unpublished document.

Forterra “Tree-iage” grid. Source: GSP Unpublished document.

To place an HMU into the tree-iage grid, the observer follows the flow chart in below. North Beach Park has a native canopy of greater than 50%, but the tree regeneration rate is very low. At the start of restoration, almost the entire park had areas of greater than 5% invasive cover, and many areas had greater than 50% invasive cover. This put most of the park in square 6 of the tree-iage grid. As of summer 2014, some areas (the areas in blue in Figure 4, below) have moved into square 4, and some areas that were in square 6 have moved into square 5.

Source: Green Seattle Partnership

Source: Green Seattle Partnership

Phases 1-3 Mapping and Assessment

Once restoration begins, that area is mapped as a restoration site in the larger HMU zone. Many large parks have HMUs of several acres, and restoration sites within those HMUs as large as the largest HMU in North Beach Park.
Green Seattle Partnership has four phases of restoration, to track and evaluate progress as a site is restored. The phases are listed in Table 1, below, along with their estimated average labor investment. A restoration site always starts out in phase 1. How long a site stays in the first three phases is suggested by its placement in the tree-iage grid. With North Beach Park starting in squares 5 and 6, the table below applies pretty directly.

Phase Tasks Average Labor Investment
1 Invasive removal 400 hours/acre
2 Secondary removal and planting 100 hours/acre
3 Continued invasive removal, watering and mulching 40 hours/acre for up to three years
4 Stewardship and maintenance 5 hours/acre annually

Some acreage in Seattle has been provisionally approved for phase 4, but exactly what thresholds qualify for the transition from Phase 3 to Phase 4 is under discussion. The figure below shows the phases of restoration in North Beach Park.

Beige areas are not yet in active restoration. Phase 1 (invasive removal) is brown. Phase 2 (planting) is green. Phase 3 (establishment) is blue. Phase 4 would be dark green.

Beige areas are not yet in active restoration. Phase 1 (invasive removal) is brown. Phase 2 (planting) is green. Phase 3 (establishment) is blue. Phase 4 would be dark green.

Deciding what phase a restoration site is in is determined by a number of factors:

  • Work logs filled in by the forest steward, contract crew, or Parks staff.
  • Volunteer hours on a site.
  • GSP-protocol forest monitoring reports (discussed above).
  • Visual inspection and transect by a GSP or Parks Department employee.

After a restoration event (which includes both public work parties and any restoration work done in a park), the forest steward enters data into a web form that includes information on volunteer attendance and total hours, square footage of area cleared, invasives removed, plants installed or watered, square footage of area mulched, and amount of maintenance activities.

Visual inspections and transects are currently on an 18-24 month cycle, with preference going to sites in Phase 1 or 2. Sites in Phase 3 might receive inspection at the longer end of the cycle. North Beach Park was last visited for phase evaluation in October and November of 2013.

The inventory protocols are very similar to the forest monitoring protocols discussed above, with the difference being that the monitoring protocols apply to samples within an HMU, and the inventory is done to an entire HMU. The inventory work is done during the same season as forest monitoring, mid-May through mid-October.

Each HMU receives a profile, taken while walking a transect. Depending on the size of the zone, it also receives a number of plots that assess regeneration or tree density. Because all the HMUs in North Beach Park are less than two acres, each HMU would receive one regeneration plot and two tree density plots.

The zone-wide measurements look at slope, aspect, soil conditions, litter depth, coarse woody debris, canopy cover and average tree diameter; and then special features such as trails, camps, wetlands, or dumps. The tree assessment tallies every native and non-native tree within sight of the transect, and giving estimated heights and DBH (diameter at breast height) measurements. The vegetation assessment records species and estimated percent cover for every species intersecting the inventory line.

The tree regeneration plots are 16’ diameter circles, approximately 1/50th of an acre. Within that circle, all trees less than 5” DBH of every species are tallied and a per-species estimate of percent cover is taken.

The tree density plot starts with a tree close to the transect line greater than 5” DBH. This becomes the center of a circle, and the distance to the nearest 5 trees greater than 5” DBH is measured.

The phase-mapping assessment compares field observations of a site in restoration against work logs submitted by the forest steward. For phases 1-3, the observations are fairly basic. The assessment for phase 4 is more rigorous and is discussed below.

Phase 4 Assessment

Phase 4 assessment is a more rigorous, quantitative assessment than Phases 1-3. If a site under consideration fails to meet any of the thresholds below, it is kept in Phase 3. The tables below show the assessment thresholds for the North Beach Park reference ecosystems.

Canopy Threshold for Phase 4 Assessment

Reference Ecosystem Density (TPA) Cover Diversity Regeneration Regen. Diversity
Mesic-Moist Conifer and Conifer Deciduous Mixed Forest 100 80% 4 200 4
Riparian Forest and Shrubland 75 75% 2 125 2

Note: “TPA” is Trees Per Acre. “Diversity” refers to species diversity.

Understory, Woody Debris, and Invasive Regeneration Threshold for Phase 4 Assessment

Reference Ecosystem Cover Diversity Snag CWD Invasive Regen. Max (TPA)
Mesic-Moist Conifer and Conifer Deciduous Mixed Forest 50% 14 30 2,000 10
Riparian Forest and Shrubland 150% 14 20 3,000 10

Note: “CWD” is “coarse woody debris” and the value is linear feet greater than 5″ diameter.

The South Plateau is roughly half an acre. To apply these tables, the TPA, Regeneration, Snag, and CWD numbers would all be halved, but the percentages and diversity thresholds would remain the same.

References

Green City Partnerships. 2012. “Monitoring Data Collection Methods.” Green City Partnerships, Seattle.

Green Seattle Partnership. 2012. “Forest Steward Field Guide.” Green Seattle Partnership, Seattle.

— 2014. “Inventory Protocols 2014.” Green Seattle Partnership, Seattle.

Monitoring Protocols

Green City Monitoring Protocol

In order to evaluate progress, Green City Partnerships have established a set of forest monitoring protocols to be used in Green City restoration sites (Green City Partnerships, 2012).

This protocol establishes a 1/10 acre circle in an area just before restoration begins. The location of the plot is recorded by the GPS coordinates of the center of the circle, walking directions from the entrance to the park or a nearby major landmark, and the bearing of at least two reference objects from the middle of the circle.

The circle is split into four quadrants, and the following data are collected:

  • Height, DBH (diameter at breast height), species, and health of trees.
  • Percent cover of all shrub and undergrowth plants, native or invasive.
  • Snags and coarse woody debris, grouped into three decay classes.
  • Basic site characteristics, such as slope, aspect, soil compaction and moistness, canopy cover, general habitat type.
  • Photographs of the monitoring site are taken at the cardinal directions (Green City Partnerships, 2012).

Percent cover is usually decided by consensus of the people working on the plot, and is reported in broad categories (i.e., “1-5%,” “6-15%”) to standardize data recording across the city.

The first report establishes a pre-restoration baseline. Ideally, the plot would be visited once a year for three years during the same month of that the baseline was taken. Budget and logistical constraints make that infeasible. After the fourth visit, monitoring drops to once every five years.

Green City forest monitoring is a citizen science project. The volunteers are knowledgeable about native plants, or taking the opportunity to learn more. Many of the volunteers are forest stewards themselves.

A practical minimum for this monitoring protocol is three people: two observers and one recorder. A good number is five, which has one observer in each quadrant and one recorder. Larger groups don’t make the process happen faster, but do make the observations more complete.

The data is entered into a web form, and at the end of the summer, summary reports are sent to the monitoring team and the forest steward. GSP uses this data to assess restoration progress and to assign restoration phases to a restoration site (which is generally a subset of a Habitat Management Unit).

North Beach Park has three official forest monitoring plots, one each in the South Plateau, the Headwaters Bowl, and the Central Valley. These plots were initially established in 2012 and revisited in 2013. Two more plots, each 1/2 the standard, in the Central Valley and the 92nd St. Wetlands, were established as training exercises for an Edmonds Community College class in 2013.

The data from these reports is discussed in the “South Plateau,” “Headwaters Bowl,” “Central Valley,” and “92nd St. Wetlands” sections.

Belt Transect

Introduction

In June, 2014, forest stewards and volunteers performed a cross-gradient belt transect of North Beach Park, following the 90th St. right of way (see below). This area for the transect was selected because it crosses every gradient of the park, from highest to lowest, and three habitat management units: the West Slope, the Central Valley, and the North Slope. It is also the only cross-gradient transect route that stays completely on public property.

On the West Slope, 4’ square plots were established; in the Central Valley and the North Slope, the plots were 4’x16’. The plots were established every 40’ on alternate sides of the transect line, and situated 2’ off the transect line to avoid trampling. For each plot, we listed species found and percent cover. Per cent cover included mature canopy trees leaning over the plot. The transect provided data for comparing the unrestored state of the areas transected to their target forest types and target ecosystems. Although we were unable to take accurate GPS readings, the transect is still replicable given the definition of its space.

The green lines indicate park boundaries. The 90th St. Right-of-Way is the gap between the southern and northern halves of the park. Red lines indicate habitat management unit boundaries. (Source Green Seattle Partnership Reference Map on arcgis.com.)

The green lines indicate park boundaries. The 90th St. Right-of-Way is the gap between the southern and northern halves of the park. Red lines indicate habitat management unit boundaries. (Source Green Seattle Partnership Reference Map on arcgis.com.)

Methods

In advance of the main survey, a transect line was established by two volunteers. Waypoints were established at intervals dictated by visibility and varied from 105’ to 16’. The line was maintained using a compass.

The transect itself was done by seven volunteers. Three worked in advance of the sampling, setting up the plots. On the West Slope, because of its steepness and dense herbaceous cover, two plots, four square feet each, were set up. In the Central Valley, nine 4×16’ plots were set up. On the North Slope, eight 4×16’ plots were set up. Each plot alternated sides, and was two feet away from, the transect line. The plots were spaced 40 feet apart.

Two people did the plant identification, with one person making the decision about per cent cover for efficiency and consistency. A third person recorded all the details.

The last person recorded GSP data using the smartphone app GPS Test, version 1.2.9, by Chartcross Ltd. However, the nature of working in a ravine and the inaccuracy of the phone made this data unreliable. Despite this, given the definite boundaries of the route, we think we can replicate the transect.

The belt transect provided a wealth of data in comparison to the circle method of forest monitoring. We were able to compare results across eight plots in the Central Valley and nine on the North Slope. These results suggested methods for invasive removal and further monitoring based on the status of the areas transected. However, the logistics involved in preparing for the transect, and the size of crew necessary to implement it, make it much more difficult to execute than the circle method.

The data from the belt transect is discussed in detail in the “West Slope,” and “North Slope,” and the “Central Valley” sections.

References

Green City Partnerships. 2012. “Monitoring Data Collection Methods.” Green City Partnerships, Seattle.

September Work Party Report

Saturday, September 27th was a beautiful day for a work party — and a good time was had by all!

Friends of North Beach park welcomed 16 students from Seattle Pacific University as part of their Cityquest program: Incoming freshman students are sent to locations all over Seattle for a little community service.

Two forest stewards had made elaborate plans for the group, and we were able to keep them busy for all four hours of the work party (FoNBP events are usually three hours). We worked on the South Plateau, which is a great place for a larger work party and needs a lot of attention.

Our plan was to remove as much of the nipplewort (Lapsana communis) and herb robert (Geranium robertianum) as possible. It really got out of hand this year, and unfortunately, the nipplewort had already set seed. It’s normally very easy to remove — it’s a shallow-rooted annual, so just grasp at the base, lift, knock off the dirt, and drop it. But the seed set meant we had to remove it. I’m sure a lot of seeds got knocked off in the process, but it was still better than leaving it there. The herb robert is also easy to remove, but it needs constant attention. It can flower any time of the year, greatly outcompetes native groundcover, and even poisons the soil against other plants. It’s other common name is “stinky bob,” and it has a pungent smell when uprooted.

Our plan was to put down lots of burlap and mulch once the herb robert and nipplewort had been removed. To which end, we had a truck full of burlap.
Tools and burlap

And a big pile of burlap and a lotta buckets!
Assemblage

In fact, about lunchtime we went back and got more burlap. And we had a group of students moving mulch from another location, adding it to the pile above pretty much all day (okay, we fell a little short on the wheelbarrows).

Speaking of lunchtime, it gave us all a chance to sit down and for the students to get acquainted with each other a bit.
Lunch

After lunch, it was back to the work: removing nipplewort and herb robert, putting mulch around already-installed plants, and building some ivy platforms.

Here is a group of volunteers in the basin of the South Plateau. When residents of Labateyah began working in the South Plateau in 2012, this was an impenetrable mass of blackberry and ivy that one forest steward thought it would take years to clear.
The South Plateau

By the end of the day, we were definitely dragging. But we had enough energy to smile for a group photograph.
The valiant crew!
Morry (in the back left), Tad (on the right, in a white hat) and Wenny (first row right, in the fuschia hoodie) were from Friends of North Beach Park. Everyone else is form SPU!

Thank you, SPU and Cityquest! We look forward to hosting you again next year.

(As usual, there are some more photos on Flickr.)

Target Forest Types

“Target forest types” are reference communities for the forest steward to target in their plant selections.

The “forest type” is based on research by Chappell (1999, 2006) for the Washington Department of Natural Resources. Each forest type is based on an observed community in areas that are as undisturbed as possible. Chappell’s research concentrates on the Puget Trough Ecoregion (the lowland areas surrounding the Puget Sound), the region Seattle occupies. Selecting which forest types specifically applied to Seattle was based on research by Larson (2005) and by using a key based on GSP inventory site data (Denovan 2012). There are currently twenty-three target forest types assigned to Seattle forests and natural areas. Four of these (discussed below) have been assigned to North Beach Park.

The name of the target forest type is derived from the dominant plant species at every canopy layer. The species are listed by their four letter code in the order of constancy with which they occurred in the sampled plots. Dashes separate species at the same canopy layer, slashes separate canopy layers.

For example, “THPL-TSHE/OPHO/POMU” is THuja-PLicata – TSuga HEterophylla / OPlopanax HOrridus / POlystichum MUnitum” (Western red-cedar – Western hemlock/Devil’s club/Sword fern). This means that there was more Western red-cedar than hemlock in the sampled plots, Devil’s club is the dominant species at the shrub layer, and sword fern the dominant species at the groundcover layer.

A long list of forest plant associations can look bewilderingly similar. The diversity comes with the non-dominant species, especially at the herbaceous level.

Why Target Forest Types

Target forest types were selected by Parks Department plant ecologists to promote heterogeneity among the natural areas undergoing restoration in Seattle. They noticed that, over the years at the city scale, plant selections were very similar.
At first, target forest types were promoted as prescriptive; that is, forest stewards had to consider the TFTs for their park a goal, and select their plants accordingly.

This lead to pushback and confusion from forest stewards. Now forest types are grouped into the seven reference ecosystems as a more general planting palette. Of the two reference ecosystems for North Beach Park, “mesic-moist conifer and conifer deciduous mixed forest” has four target forest types; “riparian forest and shrubland” has nine.

All information about the target forest types is taken from the descriptions by Chappell at the website referenced below. The descriptions are attached to this book as Appendix C, “Target Forest Type Descriptions.” The TFTs are discussed in the order of number of HMUs to which they are assigned.

TSHE-PSME/POMU-DREX

This target forest type is assigned to the following HMUs: North Slope, 91st St. Slope, West Slope, South Slope, South Plateau.

This forest type is dominated by Western hemlock and Douglas-fir at the canopy level, with sword fern and spreading wood fern at the ground cover level. It is found almost everywhere in the Puget Trough except in San Juan County.

This association is found in moist sites with nutrient-rich soils, and more commonly on lower slopes and riparian terraces. This relates well to the reference ecosystem of mesic-moist conifer and conifer-deciduous mixed forest.

Other plants in this community include Berberis nervosa (Dull Oregon-grape) which grows with sword fern in many places in North Beach Park.

Chappell says that Red alder regenerate after disturbance and that alder typically die out after 80-100 years. The alder canopy in North Beach Park is very mature, and is decaying at the rate of one to three trees per year.

ALRU/RUSP/CAOB-LYAM

This target forest type is assigned to the Central Valley and Headwaters’ Bowl HMUs.

This forest type has Alnus rubra (Red alder) almost exclusively in the canopy layer, with a dense shrub layer formed mostly of Rubus spectabilis (salmonberry). The herbaceous layer is dominated by Tolmiea menziesii (piggyback). We saw this combination pretty continuously through the Central Valley during the belt transect.

In North Beach Park both Carex obnupta (slough sedge) and Lysichiton americanum (skunk cabbage) were growing before restoration, but not together. In general, the herbaceous layer in these HMUs is not as well developed as described for this community.

Chappell describes this community as existing in palustrine scrub-shrub wetlands, which fits with the riparian forest and shrubland reference ecosystem.

THPL-TSHE/OPHO/POMU

This forest type has Thuja plicata (Western red-cedar) and Tsuga heterophylla (Western hemlock) dominant in the canopy layer, with Oplopanax horridus (Devil’s club) in the shrub layer and Polystichum munitum (Sword fern) in the ground layer.

Red alder and Big leaf maple are the current dominant trees in the canopy of North Beach Park. The 92nd St. Wetlands, to which this target forest type is assigned, is the only HMU where the coniferous canopy cover is more than 10%.

Although Chappell rates this community as secure at both the global and state level, he says there are “very few good quality stands remaining.”

We attempted to reintroduce Devil’s club into the park from seed but were unsuccessful. We look forward to reintroducing it soon, perhaps as part of the Washington Native Plant Society Stewardship Grant.

TSHE-THPL-ACMA/ACCI/LYAM

This forest type is assigned to the Fletcher’s Slope HMU.

Unlike the rest of the target forest types assigned to North Beach Park, this forest type is based on research by Kunze (1994). In general, Chappell is preferred because he provides constancy across sampled plots and percent cover of all species. Kunze provides percent cover for only indicator species. All information below was taken from a PDF excerpt of her work supplied by Green Seattle Partnership.

In North Beach Park, Fletcher’s Slope has greater than 10% Western hemlock in the community, with some Douglas-fir. Kunze says either TSHE or THPL can dominate this community. Acer macrophyllum (Big leaf maple) is the dominant deciduous tree in the dryer sections of the park. Lysichiton americanum (skunk cabbage) grows throughout the park, but we have not seen Acer circinatum (vine maple) that wasn’t planted during restoration activities.

This once-common community has few undisturbed examples. Kunze describes it as occurring in conditions that are very similar to North Beach Park: on flat ground, in depressions, with small streams and seeps, with the water level at or slightly below the soil surface.

Adapting the TFT concept to specifics of North Beach Park

Examining the target forest types above against the current conditions in North Beach Park indicates that more restoration needs to happen at the herbaceous level. To date, we’ve concentrated mostly on the tree and shrub layers. We plan to increase our reintroduction of under-represented herbaceous plants.

Putting different forest types into the buckets of reference ecosystems both allows for a greater planting selection and strategy, and perhaps even a climate change adaptation.

Research with grasslands shows that productivity increases with biodiversity (Tilman, 2001). Making several TFTs available for every reference ecosystem can help with climate change and prevent biodiversity loss through both component redundancy (increased species and community redundancy) and functional redundancy (introduction of ecologically equivalent species or novel associations) (Dunwiddie 2009).

References

Chappell, C.B. 1999. Ecological Classification of Low-Elevation Riparian Vegetation on the Olympic Experimental State Forest: A First Approximation. Washington Department of Natural Resources, Natural Heritage Program, Olympia , Wash.

— 2006. Upland plant associations of the Puget Trough ecoregion, Washington. Natural Heritage Rep. 2006-01. Washington Department of Natural Resources, Natural Heritage Program, Olympia , Wash. [http://www1.dnr.wa.gov/nhp/refdesk/communities/ ].

Denovan R., and Salisbury, N. 2012. GSP Target Forest Type Assignment Key Using GSP Site Inventory Data. (unpublished document)

Dunwiddie, P.W., S.A. Hall, M.W. Ingraham, J.D. Bakker, K.S. Nelson, R. Fuller, E. Gray. 2009. “Rethinking Conservation Practice in Light of Climate Change.” Ecological Restoration 27:3 320-329

Kunze, M. 1994. Preliminary Classification of Native, Low Elevation Freshwater Wetland Vegetation in Western Washington. Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA.

Larson, R.J. 2005. The Flora of Seattle in 1850: Major Species and Landscapes Prior to Urban Development. (Unpublished thesis).

Tilman, D., P.B. Reich, J. Knops, D. Wedlin, T. Mielke, C. Lehman. 2001. “Diversity and Productivity in a Long-Term Grassland Experiment.” Science, Vol. 294, 843-845

Habitat Management Units

Green Seattle Partnership splits each park into different zones called “habitat management units” (HMUs). This allows GSP to assign different target forest types and reference ecosystems to the different HMUs, and the forest stewards to use techniques and approaches best suited to each HMU.

North Beach Park is split into 11 HMUs; nine of these are discussed in this document. The other two are only accessible by crossing private property lines.

The HMUs were delineated by Nelson Salisbury and Ella Elman when they mapped North Beach Park for EarthCorps in late summer of 2011. The names of the HMUs were decided by the forest stewards. All of the names are descriptive in some way.

The HMUs in North Beach Park are based on two basic characteristics: slopes and uplands, and wetlands. There is some mixture in that all the wetland areas contain some upland slopes, and the upland areas frequently contain some seeps or wet areas in their lower regions.

Within these two divisions, slopes and uplands are assigned their name based on nearby property (ie, Fletcher’s Slope is below Fletcher’s Village; 91st St. Slope is below 91st St.; 92nd St. Wetlands is below 92nd St.), characteristics (the South Plateau is the largest flat area of the park and 80 feet above the rest of the park), or aspect (South Slope, West Slope, North Slope). The Headwaters Bowl is where the groundwater enters the park and begins to form the stream; the Central Valley is in the middle of the park.

Each of these HMUs received a reference ecosystem at the time of mapping, based on broad category of the plant species seen. There are two reference ecosystems for NBP: “mesic-moist conifer and conifer-deciduous mixed forest” and “riparian forest and shrubland.” These are based on NatureServe classifications.

The table below shows the nine HMUs discussed in this book sorted by size, and listed with their target forest type and reference ecosystem. The target forest types are explained in “Target Forest Types,” next week.

Name Size Target Forest Type Reference ecosystem
Central Valley 1.97 ALRU/RUSP/CAOB-LYAM Riparian forest and shrubland
Headwaters Bowl 1.39 ALRU/RUSP/CAOB-LYAM Riparian forest and shrubland
North Slope 1.14 TSHE-PSME/POMU/DREX Mesic-moist conifer and conifer-deciduous mixed forest
West Slope 0.84 TSHE-PSME/POMU/DREX Mesic-moist conifer and conifer-deciduous mixed forest
South Slope 0.76 TSHE-PSME/POMU/DREX Mesic-moist conifer and conifer-deciduous mixed forest
92nd St. Wetlands 0.69 THPL-TSHE/OPHO/POMU Mesic-moist conifer and conifer-deciduous mixed forest
South Plateau 0.57 TSHE-PSME/POMU/DREX Mesic-moist conifer and conifer-deciduous mixed forest
91st St. Slope 0.54 TSHE-PSME/POMU/DREX Mesic-moist conifer and conifer-deciduous mixed forest
Fletcher’s Slope 0.53 TSHE-THPL-ACMA/ACCI/LYAM Riparian forest and shrubland

The Central Valley, Headwaters Bowl, and 92nd St. Wetlands are all primarily wetlands and are discussed first. The other six HMUs are primarily uplands and slopes and are discussed after the wetlands. Within each category, the HMUs are discussed in the order of greatest amount of restoration effort they have received.