A World of Diversity

General Ecology

Specific Ecosystems

Twenty Years Later

Quicktime VR 360' Panorama	Mount St. Helens has changed dramatically since the May 18, 1980 eruption. Plants and animals are beginning to rebound and the slopes of the mountain are showing color again. This is an excellent chance to observe ecological succession, since the variety of ecosystems is diverse and varied in size and complexity of the destruction. From scorched trees to a blank slate of ash and pumice, Mount St. Helens has a wide variety of ecosystems to study.
Now after twenty years of recovery, even the desolate pumice plain is beginning to show signs of life. Elk, coyote, and small mammals have begun to visit the Pumice Plain, and several species of birds have begun to nest there. Spirit Lake, which is still covered with a raft of floating wood, is teaming with western toads and salamanders.
The pumice plain has been thoroughly studied since the eruption. Many scientists feel it is an ideal ecosystem to study since it was essentially a blank slate after the violent pyroclastic flows which created it subsided.
The very first plant to move into the pumice plain was the prairie lupine (Lupinus lepidus). Pearly everlasting and fireweed have followed the lupines. In some places on the pumice plain, there are small springs, which gurgle and bring water to the dry desert like sand. Along these springs and streams life abounds, willows have begun to grow. Within these willow stands, small animals such as the deer mouse, the Towbridge shrew, the pacific jumping mouse and the golden mantled ground squirrel live. These are just a few of the animals, which are moving onto the pumice plain, but there has been no recolonization of the by the stream amphibians. Although the stream amphibians have not rebounded, the populations of western toads in small lakes on the pumice plain are the highest in the entire species range; this is due to the fact that the toad's natural predators have not yet moved onto the pumice plain.
Along with the fact that the western toad tadpoles require algae to feed on and the sun blanked lakes teeming with algal growth, nourishing large frog colonies.
QuickTime VR 360' Panorama (1) QuickTime VR 360' Panorama (2)	Along with the western toad the Northwest salamander and other amphibians are flourishing in the newly formed lakes, of Mt. St. Helens. Many lakes and wetlands also formed between the hummocky deposits, which were formed during the debris avalanche, of the eruption. These wetlands are flourishing with life. Charlie Crisafulli a forest service biologist says the Northwest Salamander has been a real success story. Since the larval form of the salamander was in lakes, which were covered with a thick sheet of ice, it survived. When the ice melted the salamanders emerged, and spent the first few years around the lakes, reproducing.
Not only is it amazing that any animal survived the blast, but the salamanders which normally spend 15 months in water as they develop into adults, then they move out of the water and reproduce, have adapted. The salamanders around Mt. St. Helens have kept some of their larval characteristics, so they are able to live in the ponds and still reproduce. Sometimes one of the salamanders may start out on a journey to find a new home.
Many of the salamanders have found protection from the harsh climate in the tunnels of northern pocket gophers, the salamanders are able to find refuge in these tunnels as they travel, and can be found miles away from a water source. It is the combined effect of these surprising circumstances which make Mt. St. Helens so interesting. Not only have pocket gophers aided in the dispersal of amphibians, they also mix the new, ash with old top soil, which provides a place for new plant and animal life to take hold.
	Even the old logs which lie blown down have acted as lifeboats. Insects have burrowed into the decaying wood and provided a food source for birds allowing life to sprout up within the devastated zones surrounding Mt. St. Helens. This growth of life from within the blast zone, caused the spreading of plants and animals from all directions rather than, just working its way in form the edges of the destruction. Life on Mt. St. Helens is rebounding more rapidly than expected.
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