Question

what do living things depend upon humans for?

Answer 1

That is actually a rather hard question, considering that for the large part the only reason many ecosystems are human-dependant is because of humans in the first place. I would say for moving species into areas where they would otherwise not be able to exist due to fragmentation of their original habitat in order to ensure their survival (which I might add hasn't been very successful). I seem to be drawing blanks beyond that... what ideas do you have? :)