I completely agree, Q. I see us as human. I believe we are to be the stewards of God's creation, the earth. I don't think God created the earth for us, but rather that He created us for the earth. We're on a lease program here. God is the landlord and we are just tenants.
In my experience, all nature is sentient. Animals and trees have spirits, feelings, even thoughts and wisdom. I know that is a weird worldview for a Christian, but it is what I have experienced. That said, animals of various sorts and trees and us humans have different wisdoms, gifts, and capabilities (both individually and as groups). In my opinion, you are right that humans alone seem to possess the gift and curse of having the capacity to heal and to destroy earth. And I believe that what we do with this earth is a moral issue that God cares about.
I also agree that we have the choice whether we act like fools, wantonly destroying the tremendous gift and responsibility that is our earth, or like Messiah, healing the earth. Healing the earth, for me, is not fluffy tree-hugging (though I've hugged trees

- they're typically pretty nice folks). It is finding, as many indigenous/traditional peoples did, the balance in the web of life between taking what you need for survival, and giving back respect and responsible care. We humans are part of nature too, and we deserve to survive and prosper as well. But I don't put us as higher in priority (or even higher in wisdom) than the rest of nature, but rather only higher in responsibility. Native peoples the world over did not sacrifice their own survival for the good of the earth, but rather recognized that their own good and the earth's good was one and the same. Conserving for the earth is conserving for one's future generations, and vice versa. I would also agree with you that humans these days and in this culture have problems with sacrifice and cooperation. We have a very materialistic, now-oriented and self-centered culture, and we see the results not only in the environment but also in our society. For me, this comes down to a spiritual foundation (though I know atheists for whom it comes down to a scientific foundation). In Christ I gain a vision of Messiah that points toward sacrifice, humility, love, self-control, cooperation, peace... and I find inspiration and encouragement in that vision.