FIA: forest inventory & analysis

Three university students, Nate, Ben and Maggie, are working this summer to inventory the old-growth forest, extending the work begun in 2024, all led by UW professor Tim Billo.

Circular sites, 60 feet in radius, are laid out in a grid across the forest. Each site is assessed for trees, shrubs, understory, ferns and “coarse woody debris”. They follow the US Forest Services PNW FIA protocol – with some Seward-specific extensions.

Our goal? To capture the state of the forest in fine detail, so that future changes in the forest can be measured against this baseline.

Generous donations to FoSP fund this project. Thank you!

Green circles: 18 sites assessed in 2024. Red: candidate new sites.

Best of Intentions. Damage Done.

As readers of this website will know, many of us work hard to restore bare ground when it develops in Seward’s small, threatened old-growth forest.

Here’s why. Bare ground is dead ground – biologically inert. Fungal and bacterial populations crash/ Insects and birds have nothing to feed on. The ecological warp and weft of this already threatened forest is further reduced.

Bare ground has two principal causes: human (and canine) off-trail travel and play, and species loss (sword ferns, western hemlock, salal) maybe tied to climate change.

We are getting better at restoration planting in these bare sites – with pretty good plant survival rates – approaching 80% over the last few years.

But in a few places in the forest, and in one large area in particular, there are ongoing off-trail destructive gatherings. Long-lasting harm has been done – as the photos above attest.

These gatherings and activities likely come with good intentions. Perhaps some ceremonial context is involved: a gathering of forest enthusiasts seeking connection to the natural world in this 500-year-old forest.

But the harm to the forest is clear. Branches are collected and structures built. Recently, cedar bark has been stripped. Small fires have been set.

We understand the intention. In fact, many of us share that intention..

But the harm is ongoing. It is accelerating. It poses a threat to the forest we all value.

We need a remedy. But it is not yet clear how to proceed.

Valentine’s Day Planting Work Party

A stalwart crew, young and old, spent a sunny afternoon planting the last of 400 understory plants into carefully prepared, year-old deep mulch. We will water these plants weekly for a couple of years through the summer drought, hoping to approach 100% survival.

The Overview

Bare ground in Seward’s old-growth forest is created in two ways: off-trail travel and play; and sword fern die-off. We figure that bare ground is biologically inert ground – that is, dead ground. To stave off the possibiliyty of cascading ecosystem degradation, we mulch, we plant, we water.

We are grateful to Seattle Parks, the Green Seattle Partnership, and to the indefatigable Eric Sterner for plants, mulch, cisterns and gracious support.

Interested in joining a work party? They take place once or twice a month. Send us an email.

A Natural Experiment in Sword Fern Mortality

https://pshannon.net/splitSite2025

We have been tracking, and trying to understand dramatic and novel mortality of sword ferns in our old-growth forest’s understory. Only sword ferns (Polystichum munitum) are affected.

The full twelve year project is documented here.

Two Univeristy of Washington students spent the summer surveying throughout the Puget Lowlands of Washington state, establishing that the sword fern blight is intermittently present throughout that region. This project is reported here.

At Seward Park, we have observed the “split site” (see map tab) informally for two years. This summer (2025) we approached it systematically, by

  • Mapping and classifying each of the 39 ferns.
  • Analyzing the soil in each half

The site provides a natural experiment in that the two halves have

  • apparently identical abiotic conditions,
  • are equal in sword fern density and count
  • are separated only by one meter horizontally
  • have the same slope and aspect
  • have no obvious canopy differences (though month-by-month insolation data have not been collected)
  • are separated only by a fallen Douglas-fir log which, in the site, has a ground clearance averaging three inches (need to verify this!) allowing easy passage air, insects, small mammals and rainwater.

Nonetheless, and for several years, sword mortality is dramatically different between the two halves. The remnant dead fern crowns (dark grey markers on the map) indicate that mortality struck here three-to-five years ago. This summer (I write in September 2025) a few of the “healthy side” ferns show their first signs of blight.

On the affected half-site, the survival of 3 of 21 ferns (14%) fits our informal sense that even in heavily affected pure stands, and perhaps due to genetic variability, 10% of the stand survives the blight.

A simple chi-square calculation shows that the significance (p-value) of the separation is 4.887e-07. In lay terms: there is 1 chance in two million that this contrast happened by chance.

Thus this site, judiciously studied, and with many conditions and features identical, and dramatically different outcome, may help us to understand the nature of the sword fern blight.

Results of Soil Tests Conducted Separately on the Two SubSites

Four soil samples were collected on each subsite, to a depth of three inches. These were pooled to create two aggregate samples, one for each side, and sent to EarthFort of Corvallis Oregon for analysis.

Meeting Minutes: 12/14/24

Submitted by E. Van Volkenburgh

Attending: Lizbeth Coller, Paul Talbert, Al Smith, Ted Weinberg, Chris Hollinger, Paul Shannon, Nate Butcher, Liz Van Volkenburgh.

Paul Talbert called the meeting to order at 9:35 am.

Announcements. Paul Talbert moved that renew our business license. Moved, Voted, Passed (MVP) Paul also announced that FoSP must file a Beneficial Ownership form, related to its 501c3 status. This will be taken care of by Paul or Lizbeth.

Audubon Update. There was no Audubon Update as Joey was not present.

Monthly Reports. Lizbeth gave the Treasurer’s report: FoSP has $62,974 in its budget. A check for $960 has been written for Dylan Mendenhall for his contracted work on the sword fern sequencing project. Two donations have been received with no restrictions ($250, $5000). The Secretary’s report written by Patty Borman was emailed to the Board members on November 18. With no objection, those minutes stand approved.

Luminaria. The Luminaria organized for November 30 by a neighbor, Meghan Austin, and supported by several volunteers from the Board was a success. People coming to see the Christmas Ships were pleased and offered many thanks. Paul Talbert will send a thank you note to Meghan.

Sequencing update. Paul Talbert had sent out an update prior to this meeting and reviewed that for the Board. Paul Shannon objected to approving Dylan Mendenhall’s progress as “OK” stating that Dylan is 4 months behind schedule. After considerable discussion it was agreed that Paul Talbert would reach out to Dylan by phone to let him know there is a check in the mail for him ($960) and to share the Board’s frustration with Dylan’s slow progress. It was further agreed that by January 15 Dylan must show evidence (e.g. a photograph of bands on a gel) of successful bacterial, fungal and/or oomycetes amplification from his samples of fern fronds. In the event that no microbial DNA is amplified, the question of whether to proceed will come to the Board for a decision. The issue is whether the Board will want to risk funding DNA sequencing on samples that Dylan was unable to amplify microbial sequences from. In conversation with Dylan, Paul Talbert would also offer him an off-ramp to exit the project. Paul Shannon discussed options for pursuing the project with other labs and was encouraged to seek a bid from Dr. Marianne Elliot at WSU. Another option would be to approach Dr. Ryan Kelly at the UW eDNA Collaborative via Tim Billo.

Richard reported the discussion about speed bumps from the WDOT meeting with Seattle Parks. The meeting was organized with group work and reporting out but was quite contentious.

Forest Report. Paul Shannon reported that work parties have been happening every month following a gardeners’ strategy to mulch one foot deep, wait a year, then plant. So far, this strategy has been successful for revegetating parts of the park. Nate Butcher provided a brief update on his research project supervised by Tim Billo making a baseline vegetation survey utilizing 18 randomly positioned plots. Nate will provide a formal report in January. He is also seeking assistance with analyzing the data with appropriate statistics.

Other business. Paul Shannon asked for time to brainstorm creation of a 500 year plan as an update to the Vegetation Management Plan made in 2006 by FoSP with support of Seattle Parks. This idea was discussed and clarified – the intent is not to specify what will be planted when or what the park will look like in 500 years, but rather is to specify how to figure out what steps to take to keep the vegetation healthy. These ongoing management processes could include surveys, research studies, implementation of plans known to be successful in similar situations, etc.

Sword Fern DNA

We have wanted to do this for ten years, and finally the day has arrived. Our documentary film helped us to gather $15k, so on September 17th, Dylan Mendenhall of Haven Ecology collected sword fern tissue samples. We hope to identify contrasting microbiomes by comparing diseased tissue (from an active die-off site at Seward) and healthy controls (from Seattle’s Interlaken Park). Our informal studies suggest that the ferns are being killed by a water-borne pathogen, or by the loss of a protective microbe. DNA sequencing may identify the species.

Dylan is now extracting DNA for submission to Dalhousie University, where PCR amplification of fungal, bacterial and oomycetes primers prepare for sequencing. Dylan will analyze the data, with results ready by the end of the year.

The sword fern die-off is now broadly recognized as a regional problem, common across the Puget lowlands. Nonetheless, this loss of a foundational PNW forest understory speices has failed to garner interest and funding from government and academic researchers.

That may change. Washington’s Department of Natural Resources and UW researchers tell us they will be interested in following up if we obtain significant results.

Hemlock Study 2024

Three students, UW’s Dr. Tim Billo, forest steward Paul Shannon, 500 hours of field work, 724 trees. We determined that hemlock mortality is concentrated in one six-acre site, with thriving hemlocks elsewhere, of all ages. This establishes that neither climate nor old-age is the cause. And it presents an opportunity for further study. Something is killing hemlocks, but it is not weather patterns, soil, geology or old age. The final report, with interactive map, data table, and statistics is here. DNA sequencing of failing hemlocks and sword ferns scheduled for this summer.

Monthly first Saturday Work Party

We held our first this past weekend, April 6th – to repeat every first Saturday of the month, year round. Email us if you wish to be on the notification email list.

Here are some of the volunteer crew, relaxing after moving a ton of mulch into the Fairy Tree play area. We have two goals: to keep this spot safe, open and for kids, and to protect the forest from enthusiastic overuse.

With this final result:

We also built a brambly barrier to protect this year’s new planting near the Hollow Tree, another favorite kid play spot, on the Woodpecker Trail.

Oregon Ash Disease – transient, we hope

Full account here.

12 September 2023: Leaves with distorted shape and size dominate parts of many of the forest’s Oregon Ash trees. Total foliage in some is sparse. I think the initiation of further distortion ended with the summer dry period. The trees otherwise seem healthy. And if protracted spring/early summer rain recurs only infrequently, in future years, I predict no lasting harm to this species. I will continue to watch.