Seattle from Jose Rizal Park. Source: Flickr, David Sprankle.

Short Summary

The Puget Sound Region is a major trade gateway as well as a center of technology and performing arts. The region’s mild, temperate, and marine climate allows outdoor recreation all year, from hiking to rock climbing. The region's largest city is Seattle, with a population of about 737,000. Seattle is home to hundreds of parks including the largest public park, 535-acre Discovery Park, which contains nearly 12 miles of walking trails along the shoreline. Communities and individuals in the region have already been experiencing increased temperatures, increased summer drought, more than 6 inches of sea-level rise, and more extreme weather events in recent years. Understanding key climate impacts and tree species vulnerability are critical to urban forest management and enhancing the benefits of urban nature for residents of the Puget Sound Region.

Tree Species Vulnerability

By the end of the century, The Puget Sound Region is projected to shift from hardiness zones 8-9 to zone 9 completely, and from heat zone 2 to heat zones 3 (RCP4.5) or 6 (RCP8.5), depending on the climate change scenario. Species distribution modeling suggests that the changing climate will shift suitable hardiness zones for various tree species in the Puget Sound Region, while all assessed species are considered suitable under the projected heat zones through the end of the century. Climate change vulnerability of urban trees, including adaptive capacity and zone suitability under low and high emissions scenarios, is outlined in the tree species handout below.
Washington Park Arboretum. Source: Flickr, Steve Ginn.
Puget Sound Sail Boat. Source: Flickr, Wonderlane.

Climate Change Impacts

Key climate impacts in the Puget Sound Region include increased temperatures, more frequent extreme heat events paired with urban heat islands, increased drought risk, invasive plant species, pests and pathogens, sea-level rise, changes in hydrology leading to changes in forests and salmon habitats, increased precipitation resulting in increased stormwater runoff and erosion, and more frequent and intense precipitation events that may lead to prominent flooding.

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Work With Us

To learn more about this project, contact Leslie.