Saturday, September 2, 2017

2 new reports; hypotheses now organized

Reports of plausible, small die-off sites have come in from Blakeley Harbor, on the southern part of Bainbridge Island, and Timberlake Park,  Issaquah.  I have not yet visited these sites.

We now have a web page on which we collect hypotheses to explain the die-off.  None have yet been validated.

Friday, July 14, 2017

Regional Map of Confirmed and Candidate Sword Fern Die-off Sites

  1. Seward Park, 15 acres, first observed 2014, severity 10
  2. Suquamish (private property), 2 acres, 2010, severity 10
  3. Indianola > 1 acre, 2017, severity 8
  4. Port Ludlow, private forest, 0.5 intermittent acres along a trail, 2017, severity 8
  5. Cheasty Mt. View, a Seattle Park, ~0.5 acre, 2016, severity 6
  6. Upper Luther Burbank Park, Mercer Island, 0.1 acre, 2016, severity 6
  7. Baring, private property, 0.1 acres, 2016, severity 5
  8. (Rochester, unconfirmed, > 1 acre, 2016)

Confirmation of Two New Die-off Sites: Baring and Port Ludlow

Tuesday (July 11th) of this week I visited two new candidate die-off sites:

  • A vacation home's yard outside of Baring, Washington,  about 25 miles west of Stevens Pass.  This is at present a minor site, but interesting due to its location: far from any previously previously reported sites, disconcertingly close to the Cascades.   There are bout 30 dead ferns in a few clusters.  All ferns observed on neighboring properties are healthy.  First observed in 2016.  
  •  A private second growth forest near Port Ludlow, Washingtion, 80 miles west of Baring, 20 miles north of the Kitsap sites documented below.  Extensive die-off along 200 yards of trail.
Though neither of these sites meet the stringent criteria I have previously proposed(400 sq. ft., symmetrical,  high density, formerly uniformly sword fern understory), I judge both to be convincing instances of the die-off we see elsewhere.    

Two Short Videos from Baring

One Longer Video from Port Ludlow

Monday, July 3, 2017

Dan Hinkley's Interesting Conjecture

At risk of offering a suggestion that has more than likely already been examined as obvious, the photos in your blog appear as if we might be dealing with a mycelium complex in the soil that has made the edaphic environment hydrophobic.

It appears as if nothing is regenerating, making it seem evident that the pathogen is not conspecific to Polystichum but simply establishing in Polystichum-friendly habitat. 

Have any observations been made of fungal fruiting bodies on the outer edge of the infection sites or have soil samples been examined for the presence of mycelia?  This has the gestalt of a ‘fairy ring’ in a lawn.  Has anyone attempted to mechanically aereate the Hatchery Creek site to see if something will again begin to grow?  The dead zone can seemingly only point to a hydrophobic condition, or to an unlikely pathogen that kills everything in its wake and disallows anything to reestablish.

Port Ludlow report by Jim Gormly

Beyond Kitsap Peninsula, across the Hood Canal, there is a greenbelt in Port Ludlow, ca. 2000x400 feet. It is a second-growth forest primarily with western red cedar, douglas fir and large-leaf maple trees. It is mostly shaded, but there is the occasional small open area free of trees. The understory is mainly sword fern, salmon berry, blackberry and other nasty vines. Apparently, a few years ago a beetle infestation caused the death of a large number of alders.

Yesterday I became aware of an area, perhaps 75x25 feet rectangle of dead ferns. I estimate that more than 50 plants were obvious. Since I don't know how the problem is transmitted, I chose not to be a vector, just in case it might be a spore transfer, so I didn't climb in to get a more accurate number of dead ferns. Throughout the greenbelt, there is the occasional dead or dying fern, but this is clearly the largest concentration I observed. There was also a dying salal plant among the cluster of dead ferns (see photo). I'm sorry the exposure is not the best.

When I saw the dead ferns, my first reaction was that someone dumped a herbicide, but that made no sense, so I did a Google search and found your blog. I must say that this is very disconcerting. I hope you find a solution. I will continue to monitor here, and will update you as time passes. . We have extensive greenbelts here with trails through them, and many residents enjoy walking the trails. It would be a sad loss if the apparent trend continues. 

Jim Gormly

Regional Map (Verified and Candidate Sites)

An informal regional Puget Sound map, with dots showing verified and candidates die-off sites, size and color a very rough indicator of status and severity.  Small, unverified sites may not stand up to scrutiny.
  • Seward Park (first reported 2014, 15 acres, verified, spreading)
  • Suquamish (2010,  2 acres, verified, spreading)
  • Indianola (2017, < 0.1 acres, not yet visited)
  • Cheasty Mountain View (2017, 0.5 acres, verified, spread status unknown)
  • Mercer Island Upper Luther Burbank Park (2016, < 0.1 acres, verified, spread status unknown)
  • Port Ludlow ( 2017,  < 0.1 acres, not yet visited)
  • Baring (2017, < 0.1 acres, not yet visited)