How do food webs, ecosystems, and the carbon cycle relate?

Which best describes the scientific process

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight. which of these is the most likely effect on the ecosystem? a-an increase in biodiversity. b-an increase in immigration to the area. c-a decrease in available water. d-a decrease in plant growth.

What is the importantence of the carbon and nitretan cycles in the environment