Reddit reviews A Natural History of Western Trees

I did the bio route, specifically botany. B_Prov has a great list, but my 2 cents: The origins go back to native American traditions of animism. Trying to find some quality and formative ethnographies on their world view may give you more of a chronistic context.

Many of the modern romance authors are, sort of, a proto-revisitation of those themes. Thoreau is solid (you can certainly pick apart things, but his premise is solid). I second Muir, and Leopold. Sand County Almanac was the precursor to the modern environmental movement and the foundations of deep ecology. Again, this is a more articulated 'white-man's' animism. Edward Abbey is a bit more cynical, but also a better author then many of his predecessors.

That said, here are a couple that you may find interesting as a biologist:

Gathering Moss

lives of a cell

Natural History of North American Trees: 2 vol ,

The Immense Journey

Oddly, I thought Vonnegut's Galapagos was riveting.