I don't think it's a good idea to act like human beings doing things in the world are something different from the environment or ecosystems.
there is no escaping from value-judgments, even from things that one thinks are natural such as environments. But weighing the pros and cons and having knowledge of what is occurring is very important. I don't know how well human beings can really judge what is best for the entire systems of the world.
There are always going to be philosophically assumptions about what a person thinks nature should be like. Nature changes all the time. one environment shifts into another and yet some would like to stop this natural shifting of one kind of environment turning into another as if nature is some abstract static entity. In reality abstraction is a thing of the human mind.
just because grizzly bears used to be in California does not mean that they should be there or that they should be reintroduced. human beings matter more than a small idea of what it means to preserve the environment.
I'm certainly not trying to say that you're wrong, as if anything is as simple as a "you are 100% wrong or right." I find myself overwhelmed by reality and it becomes very hard to judge what is best.