Sword ferns provide valuable ecosystem benefits, holding soil in place to prevent erosion and invasive plant growth. They also provide a habitat for forest birds such as the Pacific wren, and a food source for wildlife, such as mountain beavers. And in Seattle’s Seward Park, they are dying off at alarming rates.

Nobody really knows why, but Program on the Environment lecturer Tim Billo and Seward Park steward Paul Shannon have some ideas, which they shared with King 5 News reporter Alison Morrow last Friday. Check out the video.

Paul Shannon (2011), Jordan Jackson (2017).

According to Tim, sword ferns are just not regenerating. He’s been monitoring the decrease of ferns in Seward Park for the past two years to measure the rate at which ferns are dying, and to identify any known causes. Paul Shannon has noticed the decrease of ferns in the area for even longer and predicts all the ferns in the park could be gone in 10 years. There are concerns about the reverberating impacts of this unnatural phenomena, which may have implications in other parts of the region.

With Tim as his faculty advisor, Environmental Studies student and recent graduate Justin Beach investigated the fern die-off phenomenon as part of his Capstone project, and tested the effects of native mountain beavers on the ferns. Beavers are unlikely the cause of the die-off and are at risk if this primary food source is less available to them. There may be an as of yet unknown pathogen that is preying on the swordfern. Continued research is needed to save the ferns. Read more about Tim’s research on the sword fern die-off in one of Seattle’s beloved parks.