What are the functions of ecosystem?

In an ecosystem:

Ecosystem is

Describe structure and function of an ecosystem.

Which one of the following is not a functional unit of an ecosystem?

Poaching of a tiger is a buring issue in today's world. What implication would this activity have on the functioning of the ecosystem of which the tigers are an integral part?

Name three important functions of an Ecosystem.

Name the three functional groups of an ecosystem?

What are anthropogenic ecosystems?