Semiosis by Sue Burke
Semiosis is less a novel than a book of short stories, each of which recounts another generation of the history of a human colony on an exoplanet. I had trouble with the beginning, but after I understood how the story was being told, I had a lot of fun.
There’s some very good speculative biology here,. The animals and plants feel very real, and lovingly developed. The philosophical heart of the book is about trust – how can mutualism develop between sapient species? With great difficulty.