Symbolism, Imagery, Allegory
Speaking of Nature with a capital "N," we have to talk about the importance of The Chase. After all, one of the most important scenes of Tess's life takes place there. The Chase is all that remains of the ancient, primeval forest that used to stretch all across Wessex, the fictional county where all of Tess of the D'Urbervilles takes place.
Why is it important that The Chase be so ancient? Well, one reason might be that the ancient-ness of The Chase provides a stark contrast to the surprisingly modern house that Alec D'Urbervilles lives in. The Slopes is brand-spanking new: "everything looked like money—like the last coin issued from the Mint" (5.22). The idea of old and new, past and present, nature and civilization somehow overlapping or coexisting is one that Hardy brings up again and again.