Goat Marsh Research Natural Area is a 1195acres research natural area located southwest of Mount St. Helens and within Mount St. Helens National Volcanic Monument. The natural area is composed of wetlands, young conifer forests growing in volcanic soils, and old-growth stands of superlative Noble Fir and Douglas Fir.
The area has been identified as a region of scientific importance and preserved for ecological research due to its recent volcanic history as well as for its large tracts of mature and undisturbed Noble Fir forest.[1]
The wetland and Lodgepole Pine forest ecosystems of Goat Marsh RNA were established in between approximately 1550 and 1700 C.E. when pyroclastic flows triggered by the eruption of Mount St. Helens disrupted the hydrology of Cold Springs Creek. These ecosystems comprise the majority of the natural area, about 780acres.
The remaining 365acres located on the northern edge of the NRA is dominated by a 350 year old forest of Noble Fir and Douglas Fir that were spared by recent volcanic eruptions. This temperate rainforest contains tracts with average canopy heights of 213abbr=offNaNabbr=off[2] and 44,584 cubic feet per acre (3,120 cubic meters per hectare) of living terrestrial biomass—the highest in the Pacific Northwest outside of the "Redwood Belt" of Northern California and among the highest the world[3]
Goat Marsh RNA contains many of the largest and tallest remaining specimens of Noble Fir, including the "Goat Marsh Giant" (272 ft height, 8.3 ft DBH, 4,430 cubic feet volume), "Riker!" (253 ft height, 7.3 ft DBH, 3,810 cubic feet volume) and an unnamed fir 295 feet tall.[4] This relatively small area of forest also contains Douglas Fir measured at over 300 feet in height.
Other conifers common within Goat Marsh RNA include Western Hemlock, Pacific Silver Fir, and Western Redcedar. Common understory vegetation includes Vine Maple, Vanilla-leaf, and Redwood sorel. Wetland vegetation includes various species of sedges and grasses.