What is a real life example of ecosystem

An ecosystem consists of a community of organisms together with their physical environment.

Ecosystems can be of different sizes and can be marine, aquatic, or terrestrial. Broad categories of terrestrial ecosystems are called biomes.

In an ecosystem, both matter and energy are conserved. Energy flows through the system—usually from light to heat—while matter is recycled.

Example - a community consists of all the populations of all the species that live together in a particular area. 

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.