How does a volcaneo affects the ecoystem?

Answer 1

the lava spewing out cools into rock and covers any plant life, animal life, or anything else in the way

also, the ash, smoke and debris that float around in the air can possibly blot out the sun (a little bit) or cause bad air pollution for the animals and plants

if it covers plants, animals that ate it will have less food

those animals will lose numbers and the animal that eats that animal will have less food

etc.

if it covers animals, the same thing will happen

so basicly, volcanoes negatively affect the ecosystem by destroying the food chain/web through air pollution or covering the life up with lava/rock