I guess to an extent this argument is about whether you think humans are part of nature, or above nature. I believe we are part of it, we have the same right to survive as other organisms, but also they have the same right to survive as us. As now most of the natural controls are removed on humanity, humans should set their own controls to keep us in "equalibrium" with the rest of the planet.
We our both nature and above nature. we have evolved passed the need for nature and can survive regardless.
As someone else has already said we can already save full genetics and clone. we can allready alter dna to improve species and it won't be to long before we have almost an unlimited knowledge and understanding of it.