1980 Eruption of Mount St. Helens
Cascade Range, Washington; May 18, 1980
Basic Summary
THE EFFECTS
ECOSYSTEM: BIOTIC
The fish and amphibians were killed off by the pyroclastic flow. Because sunlight couldn’t get through the debris filled water, algae died. Mammals living within the Blast Zone were killed immediately- deer, elk, coyotes, mountain lions and goats, and smaller animals- hares, squirrels and more. Beavers died as mudflows swept their dams. Millions of insects and many birds were also killed in large numbers along with destroying hatcheries containing baby salmon. Millions of trees in forests were flattened, destroying the habitat for many organisms.
The recovery of life was a slow, amazing process...
After 3 months of the eruption, signs of freshly turned Earth appeared the work of the Northern Pocket Gopher, which hibernated underground. As these creatures moved around, they moved around a special fungus that helped provide plants with nitrogen. The mounds of soil became breeding grounds for new trees. Soon, a Prairie Lupine was found thriving because of a special root structure. The pioneering species relied on bacteria to provide it nitrogen in return for simple sugars. The nutrients added to the soil by the lupine allowed other plants to grow. Elk and deer are starting to wander in looking for food, collapsing the gopher and other animal’s tunnels. Soon after an explosion of bacteria in Spirit Lake consumed all the oxygen, the debris and ash in the lake started to clear out. Phytoplankton brought in by birds and the wind started to grow because of the sunlight, and produced oxygen. Amphibians wandered in to the lake from the collapsed tunnels and the lake is now teeming with fish brought by fisherman.
Scientists were amazed by the ecological succession and used the eruption as an opportunity to study the ecosystem.
Ecosytem: Abiotic
The water in Spirit Lake and other rivers became contaminated and wasn’t able to adeptly hold any organisms.
Also, the complete formation of the Volcano was changed due to landslides and the unusual growth of the mountain, pushing out rocks. Any rocks and other boulder type structures were also physically changed.
Also, because of the fumes and ash released, the atmosphere and climate was altered for a while.