By Tracy Record
West Seattle Blog editor
An unusual forest-restoration project – involving a significant amount of tree-cutting as well as tree-planting – is about to get under way in eastern West Seattle’s Puget Park, after three years of planning.
The project leader says it’s work that will have benefits for decades and centuries to come – but it’s a project unlike any other they’ve undertaken, and they want people to understand why it will require taking out hundreds of trees (an estimated 600 “stems” – some trees have more than one).
We went to a weekend briefing to find out more firsthand. It’s a Seattle Parks project under the umbrella of the Green Seattle Partnership, which will have 1,500 acres in restoration citywide by year’s end. The challenge here is that the area has an “unnaturally dense hardwood canopy” – far out of balance with evergreens, and bringing them back requires removing some of that dense canopy.
Here’s what plant ecologist Michael Yadrick from Seattle Parks told attendees about what’s going to be done and why:
Speaking in the Chan Education Center on the north side of the South Seattle College (WSB sponsor) campus – steps from the west edge of the forest – Yadrick said he’s been with Parks for about seven years and focuses on the west side of the city. 2,500 of the 6,414 acres that Parks owns is ‘destined for restoration’ – that’s five percent of the city’s land mass. The West Duwamish Greenbelt is four miles long, from Pigeon Point to Westcrest Park.
The city’s recent tree-canopy assessment (see a map at seattle.gov/trees/canopycover) shows that this area has a decent canopy – the highest percentage is in east West Seattle (Delridge), 38 percent, because of the natural areas like this one.
The project area is from Brandon Street south to the SSC aviation center, 24 acres, with 30 percent of the “native hardwoods” (which comprise about 95 percent of the trees in Puget Park – compared to 72 percent citywide) to be taken out, creating gaps for conifers that are there now – or to be planted – to grow. The trails in the area, by the way, are not officially part of the city’s 120 miles of trail, in part because it dead-ends and crosses some private property, it was pointed out.
The project also will include “understory treatment” – weeding out blackberry, etc. – and will be followed up with planting of 10,000 native trees and tall shrubs.
The “need to do this sort of work” was established a long time ago, Yadrick said, but it just hasn’t been done. So they started consulting and researching in 2014. He showed a list of more than 15 groups with which he’s consulted, including many tours in recent months, to “vet the concept” and “talk about what it means to folks.” It’s taken a “serious amount of consideration” because of the project’s nature.
He stressed, “It’s not a traditional ‘logging’ project” – it won’t be a clearcut-type of situation.
What happens if it’s not done? In another decade or two, “invasive plants outcompete and cover existing native vegetation, leaving little light for young plants to establish. English ivy thrives in the tree canopy, making trees top-heavy and susceptible to wind. Eventually trees die or fall over.” And then in another few decades, no trees, mostly just invasive plants like ivy. The trees that are dominant right now include red alders, which reach their maximum height in 40 years but become mature within the first eight. They need full sun, so in a conifer forest they wouldn’t take over like this. “It definitely has its place in the forest, but we’re shooting for a little more balance.” Big-leaf maples are taken over by ivy, too. To fight that, Yadrick explained “ivy rings” that can be placed – though it’s labor-intensive; he talked of an eight-acre spot that required 900 of them – Green Seattle Partnership has placed hundreds of thousands of them, he said. When they’re not full of ivy, as in other forests, they might be draped in mosses and lichens, he noted. But around Seattle, bigleaf maple and red alder are the top two “failing” tree species (followed by Pacific Madrone and Douglas Fir, Black Cottonwood, Willow, Deodar, Cherry, Western Red Cedar, Black Locust) – even though most of those are native. “The trees are just starting to fall apart.” They’re also susceptible to some diseases – he mentioned a study of “verticillium wilt” causing dieback and decline in bigleaf maple.
Back to the restoration plan, they also work to control “non-native trees,” such as English holly – “one of the more despised trees in the forest.” And when they replant, they go for shade-tolerant conifers – like grand firs – so they have a better chance of early survival. They could grow to 200 feet, but it’s slow going, and they don’t even bear seeds until they’re 20 years old. But eventually they’ll “shade out” the invasives. This is all an attempt to “jump-start” a healthy forest.
The “before” photo is more accurately, Yadrick showed, a picture from two winters ago, when the deciduous trees are devoid of their leaves, and the landscape is rather sparse looking, compared to the “leafed-out” spring and summer scene.
Part of Puget Park – to the north – has had some restoration work since 2008; the central part, for the past four years; the south part, just beginning. “The reason why we chose this spot” for the thinning project “is that it’s fairly flat,” he said. Also, not many “public hazards” since there’s “limited recreation” in the area. They won’t be cutting on the steep slopes (a map shown during the presentation showed some of them with orange – 70 percent slopes – and red coloring – 100 percent). And again, the replanting will cover 40 acres, while the thinning will cover 24. But the gap creation, and growth of new trees, also will lead to “natural regeneration” as the years go by. The conifers also will help with stormwater retention in winter rains, compared to leafless deciduous trees that dominate the site now.
So far, they’ve marked more than half the site, with paint on the trees slated for removal. A similar thinning project was done on five acres of Discovery Park in north Seattle, Yadrick said.
They won’t start the Puget Park cutting until mid-August, because of bird-nesting season. To support wildlife, he said, the snags that are already standing will be kept. And since they have “no mandate to remove wood from the site,” the downed trees will be kept on the site, creating some “nurse logs,” which are also habitat for small animals. They’ll be planting “in and around the dead wood … it won’t be an evenly spaced plantation-type situation.”
The replanting will include not only conifers but also trees that can “grow into the middle of the forest as well.”
This will be a sort of “test project,” Yadrick acknowledged in Q/A – and after this, they will “step back and assess where else we could do this” in the city, taking into account factors including public sentiment and cost.
WHAT’S NEXT: As mentioned above, the work is expected to start in mid-August. The timeline published in this detailed post on the Green Seattle Partnership website is as follows:
Carry out the thinning and gap enhancement operation from mid-August through mid-October 2017
Replanting will be complete before the end of March 2018, and
Monitoring via GSP long-term monitoring plots and inventory starting spring 2018