What does it mean to define "boundaries" of an ecosystem?

In this experiment, the was intentionally manipulated. it is the independent variable. the dependent variables that were measured were the

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight. which of these is most likely effect on the ecosystem?