An ecosystem is a complex system with many parts, both and non-living. All parts of the system are important. If one part of the system is removed, lots of other parts can be affected.
An ecosystem, with a part of it missing may continue for a while but in time would start falling apart.
All of the parts of the ecosystem work together. If you do not think about how your work will affect the land, water or air where you are working, you could damage that ‘ecosystem’ by poisoning the land or water, removing plants and trees or killing the fish, insects, birds and animals that live there.