Hardy's very interested in the relationship of women to nature, in particular. In Tess of the D'Urbervilles, women are more in touch with the earth than men are, and are able to melt into the landscape and become one with the land in a way that men cannot. Being able to stay in touch with the natural rhythms of the earth is obviously something that Hardy values in this novel.
Hardy often juxtaposes images of ancient nature with emblems of modern civilization to suggest that the progress of time is not uniform.