The Lisven is linked to the Millven with a wetland zone. It is an area with mainly dry and moist heathland. In certain periods, sheep are used here to maintain the heathland. With their grazing pattern, the sheep provide a gradual transition in vegetation (overgrowth). During the flowering period of the herbaceous plants there is no grazing. This gives these plants time to flower and form seeds, creating a more species-rich heathland.