Final answer:
Grace confesses to Parker about the sentience of the trees, paralleling Usher's belief in the sentience of all vegetable life and its connection to his family's destiny. This concept ties in with the idea that living systems possess and exchange vital information.
Step-by-step explanation:
Grace confesses to Parker about the sentience of the trees. This idea is central to the thoughts of Usher that are clearly reflected upon in the passage provided. The belief Usher holds is that all vegetable matter, and under certain conditions even inorganic matter, possesses a form of sentience, which, in his case, is deeply intertwined with the gray stones of his ancestral home and the natural life that surrounds it, including the trees and fungi.
This concept of sentience in trees and plant life echoes the Big Idea 3 from living systems which emphasizes the importance of storage, retrieval, transmission, and response to information as essential to life processes. Usher’s conviction of the trees' sentience implies an advanced form of communication or interaction within the natural environment, which could be considered a network of information essential to the life processes of the ecosystem.