Die-off at Seattle Park Cheasty Mountain View

Tim, Al and I followed up on Al's initial report of sword fern die-off at Cheasty Mt.View, a few dozen yards west of the intersection of Columbian Way and Mountain View Drive.

The area is second growth forest, mostly big leaf maple, with a mixed sword fern, Indian Plum, salal and invasive understory.

We did an informal survey of a mixed flat and steeply sloping area, about 135 feet east-west by 100 feet north-south.  We placed 110 orange marker flags at each unambiguously dead fern; closely clumped dead crowns were treated as a single fern.  We excluded any fern showing any trace of green. This yields a concentration of  ~120 sq.ft per fern - which is consistent with a second growth, mixed understory rich in ferns.  The understory of this site is decidedly not dominated by ferns in the manner that the Seward, Suquamish and Upper Luther Burbank sites are.

Tim, Al and I then each separately estimated the ratio of dead/live ferns across the  135 x 100 foot region.  This was exceedingly informal.  Our average estimate was about 50%.  We did not distinguish a third group:  affected ferns still showing some green.  That group was lumped in with the healthy ferns.

This site does not meet the six criteria - which were inferred from die-off sites in which the sword ferns been the dominant - indeed, nearly exclusive - understory plant.

We left ten short orange marker flags in ferns with medium-to-good health.  One of Tim's natural history students will do repeat photography of these ten ferns over the next two months.