Mount
St. Helens
National Volcanic Monument
Photo Library
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Mount
St. Helens |
Blowdown Forest with Plants Protected by Continuous Snowpack on May 18, 1980
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Snow-protected Pacific silver fir and mountain hemlock trees are visible (beneath log in foreground) in this 1983 photo. 77 meta ck bds 11 1983 photo
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Colonization of the blown down forest by weedy plant species like fireweed and continued growth and expansion of snow-protected shrubs and trees is evident in this forest southeast of Meta Lake. 77 meta ck bds 11 1995 photo
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The combination of live foliage from surviving trees and shrubs and abundant standing dead and downed wood have made for excellent bird habitat in blown down forest with snow. 77 meta ck bds 11 1999 photo
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As snow protected trees and shrubs produce seed, the pace of forest regeneration inside the blast zone is increasing. 77 meta ck bds 11 2004 photo
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Snow-protected Pacific silver fir trees are easily seen in this 1983 photo. 77 meta ck bds 15 n 1983 photo
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After a period of stress resulting from sun damage to shade adapted leaves, snow-protected trees were able to produce new leaves adapted to open sun. In the absence of competition from overstory trees that were blown down by the eruption, the snow-protected trees have grown quite rapidly. 77 meta ck bds 15 n 1989 photo |
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77 meta ck bds 15 n 1995 photo
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77 meta ck bds 15 n 2004 photo
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North-facing slopes such as this one on the south side of Meta Lake faced away from the blast and were cooler and, thus, carried more snow-cover on May 18, 1980. The combination topographic sheltering from blast scouring and snow-protection allowed many small trees and shrubs to survive. (blast direction is from right to left) 8 meta lk bds s2 10 e 1983 photo |
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Snow-protected trees and shrubs are readily visible in this 1984 photo. (the trees pointing toward the direction of the blast are the result of turbulence as the blast swept over the steep ridge). 8 meta lk bds s2 10 e 1984 photo
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8 meta lk bds s2 10 e 1986 photo
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Continued growth of snow-protected trees is easily seen in this 1994 photo. (note person in foreground for scale) 8 meta lk bds s2 10 e 1994 photo
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8 meta lk bds s2 10 e 2004 photo
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With the exception of a few late-lying snowbanks, this south-facing slope on the north side of Meta Lake was mostly snow-free at the time of the May 18, 1980 eruption. As a result, comparatively fewer shrubs and trees survived than on cooler north facing slopes on the south side of the lake. 8 meta lk bds n2 6 1986 photo |
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Rapid colonization of the open blast deposits by weedy plant species adapted to open blast zone conditions like fireweed and pearly everlasting is evident in this 1995 photo.
8 meta lk bds n2 6 1995 photo |
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Weedy plant species such as fireweed and pearly everlasting flourished in the open, blast area. The few trees visible along the lakeshore survived under scattered patches of snow. 8 meta lk bds n2 6 2000 photo
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Continued expansion of shrubs and in-filling by colonizing seedlings is visible 24 years after the eruption. The abundance of huckleberries, a a common shrub in the subalpine forest is evident in this photo (shrubs with red fall foliage). 8 meta lk bds n2 6 2004 photo |
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There was little snow present on the west side of Meta Lake and, consequently few plant survivors. 8 meta lk bds w 1 1983 photo
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Colonization of the blowdown forest by fireweed is readily visible in this 1995 photo. Note the scattered snow-protected trees and continued colonization by willows and other shrubs. 8 meta lk bds w 1 1995 photo
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Evidence of the 1980 eruption is gradually disappearing beneath a sea of green as the blown down trees have decomposed and have been crushed to the surface by dense winter snowpacks, . 8 meta lk bds w 1 2004 photo
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8 meta lk bds w 5 1983 photo
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8 meta lk bds w 5 1984 photo
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8 meta lk bds w 5 1989 photo
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8 meta lk bds w 5 1995 photo
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8 meta lk bds w 5 2004 photo
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Scattered fireweed seedlings were among the first plants observed on the west shoreline of Meta Lake. 8 meta lk bds w 5 e 1989 photo
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Plant survival was confined to trees and shrubs sheltered by a few remnant patches of snow and buried roots that managed to sprout through the overlying blast and airfall ash deposits. 8 meta lk bds w 5 e 1995 photo
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8 meta lk bds w 5 e 2004 photo
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03/22/2005 Mount
St. Helens National Volcanic Monument
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