"...they are clearing the swamp so fast. Every year it grows more difficult to find things, and Indian stuff becomes scarcer."
For a while in my reading of A Girl of the Limberlost it's been clear that Elnora is aware that the Limberlost is changing. But her concern is for what that means to her ability to generate income. I haven't read anything that indicates that she or anyone else has any interest in preserving the swamp at all.
When Elnora approaches the local school superintendent about getting a job, she's offered a position teaching natural history at each of the schools in the city. The value of what she knows about nature is respected. But there's no talk about preserving nature.
Elnora mounts the moths and butterflies she collects, creating collections she can sell. I can remember reading about people doing this in various books when I was young, but I can't recall anything recently. I'm assuming this is due to the fact that mounting them with pins on boards involves killing them, meaning they're being killed as trophies. This actually is addressed in a conversation between Elnora and young Billy, an orphan taken in by her neighbors. It turns out that Elnora's method for collecting her specimens meant they died of natural causes. She didn't actually have to kill them. "Between us, Billy, I think I like my old way best. If I can find a hidden moth, slip up and catch it unawares, or take it in full flight, it's my captive, and I can keep it until it dies naturally." Billy thinks it doesn't matter how she takes her moths because they die in order to educate humans. "It's not like killing things to see if you can, or because you want to eat them, the way most men kill birds. I think it is right for you to take enough for collections, to show city people, and to illustrate the Bird Woman's books. You go on and take them! The moths don't care. They're glad to have you. They like it!"
Elnora is delighted with his argument. But do the moths also like the cyanide jar that's mentioned soon thereafter? Do they like being pinned, their legs drawn into position "in perfectly lifelike manner?"
At this point Elnora is revered for her knowledge of nature. In the eyes of the young man who has joined her in her pursuit of moths, she is clearly superior to the young women he knows back in the in the city, including his fiance. But knowledge of and appreciation for nature seems to be enough. Supporting nature just isn't isn't in the cards in this 1909.
But I will keep reading.