What is the dynamic between men and women through the symbol of nature?

I'm not sure about the nature part of your question. Through the dynamics of the Blackwood family and the town as a whole, Merricat’s world is split starkly into male authority and female power. The magic that Merricat practices and believes in can be seen as a form of witchcraft, a strongly female-coded practice, and by the end of the novel, the Blackwood sisters are perceived as almost like witches by the villagers, who whisper that they eat children. Male authority, seen in the sisters’ father, John, and their cousin Charles, is strongly linked to money, which is embodied in the family safe that Charles tries to steal. This connection makes sense, given that men have traditionally been the breadwinners of American society while women have been relegated to the home. Yet it is in the home—and in food, another strongly feminine symbol—that the Blackwood sisters derive their power. By locking themselves in the home, Merricat and Constance free themselves from patriarchal male authority. Food is a locus of power for both sisters. The household revolves around the meals Constance prepares, drawing on the garden she tends and the preserves that generations of Blackwood women have created. Similarly, Merricat’s defining display of power—killing her family—occurs through her poisoning of the family’s sugar.