Overview

New Posts (please scroll down):

December 2018: request for research proposals, site visit by LSU plant pathologist

October 2018: two experiments, possible insight into mechanisms of spread

Since 2014 we have been observing and attempting to understand a dramatic die-off of the dominant understory sword fern species, Polystichum munitum, in the 120-acre old growth "Magnificent Forest" in Seattle's Seward Park. 

Please add your own observations at our iNaturalist project.

Extensive lab and field work, consultations with fern experts throughout the US, and recent reports of die-off from elsewhere in the Puget Lowlands of Washington state (see annotated regional map), lead us to conclude with considerable confidence: 

• The die-off is caused by an (as yet unidentified) pathogen 
• Climate change may be a contributing factor, but until the proximal cause of the die-off is determined, the role of climate change can not be known.  
• Drought is probably not a cause (see rainfall records below).
• Is unprecedented, not part of the P.munitum life cycle, in which ferns colonize open ground, do not reproduce under a closed canopy, with individual plants living for hundreds of years.
• Holds implications for the forest at Seward Park, and for other forests in the region.

Some selected blog entries

• A Lazarus Fern? (March 2018)
• Port Ludlow die-off, some recovery: 2010 - present
• Experimental Plantings at and near Ground Zero (March 2018)
• Hypotheses

• Die-off reported from Snohomish County, Lord Hill Park (January 2018)
• Extensive die-off confirmed on Bainbridge Island and the NE tip of the Olympic Peninsula (December 2017)
• Narrative Essay - an overview
• Soil Analysis (June 2017)
• King 5 video (2 minutes, May 5th 2017)
• KUOW (27 july 2017)
• Sierra Magazine (August 2017) by Sarah DeWeerdt
• Seattle Precipitation Records (2012-2016, evidence against drought/die-off causality)

Contact: Paul Shannon, Forest Steward