Explain how changes in an ecosystem can sometimes be and sometimes harmful

I will explain in an example a good change would be A group of kids planting trees this could make a food source for plant eating animals and it also would create more oxygen

A harmful one would be cutting down trees to make a new mall, This is the exact opposite of the one above, less food for plant or leave eating animals and less oxeygen

How either some or all of the organisms in this activity are related to one another based