Over the past two years, Forest Park Conservancy (FPC) has been working smart to combat invasive plants in Forest Park and monitor the effectiveness of these efforts.
FPC’s monitoring protocol, developed in collaboration with West Multnomah Soil and Water Conservation District, Portland Parks & Recreation City Nature West and the Green Seattle Partnership, collects data on forest maturity, invasive and native plant abundances, and soil characteristics within current and projected restoration areas.
Last fall, Forest Park Conservancy hired contractors to selectively treat over 30 acres of ivy-infested forest near Pittock Mansion and Holman Lane. FPC’s pre- and post-treatment monitoring, conducted in Spring 2013 and Spring 2014, respectively, revealed dramatic reductions in invasive plant cover. Following the herbicide treatments, many sites showed invasive ivy cover drop from over 50% to less than 5%, with minimal damage to native plant species.
Before and after shots of a restoration monitoring plot, not far from Pittock Mansion. Almost a year after treatments, the FPC Restoration Crew captured some encouraging wildlife sightings within these Forest Park restoration areas.
Pacific Tree Frog on fallen ivy leaf
Mountain Beaver Den
This summer, the FPC Restoration Crew applied the same monitoring protocol at Forest Park Conservancy’s Ancient Forest Preserve, a stand of old growth forest just three miles north of Forest Park. These monitoring data may be useful for informing old growth forest restoration in parts of Forest Park and surrounding natural areas.
With bald eagles roosting in 80-inch diameter Douglas firs and coralroot orchids punching through the duff layer, the Ancient Forest Preserve is one archetype forest worth striving for.
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