Terrestrial habitat in Puget Sound varies greatly, from alpine and subalpine meadows and evergreen forests to valleys, floodplains, and prairie. However, these ecosystems are not clearly divided but blend smoothly into each other, linked by rivers and streams and the overlapping ranges of various species, determined by their tolerance of various environmental conditions. Various approaches exist for categorizing habitat types. Franklin and Dyrness developed a system in 1973 using dominant tree species as distinguishing features. In the Northwest, Sitka spruce dominates the lower elevations, moving towards Western hemlock and Douglas fir farther from sea level. Silver fir is more prevalent in the middle range, and mountain hemlock at higher elevations. Jones (1936) established the four Merriam’s Life Zones: Humid Transition, Canadian, Hudson, and Arctic-Alpine, which are defined by vegetation patterns, precipitation, and elevation.
Sources:
Kruckeberg, Arthur. A Natural History of Puget Sound Country.1991. University of Washington Press, Seattle, WA.
Overview
Freshwater habitat in the Puget Sound region consists of rivers, marshes, streams, lakes and ponds that do not have any saltwater input. Many species depend on these freshwater resources, including salmon, salamanders, frogs, and beavers.
