The ecological value of the New Forest is enhanced by the relatively large areas of lowland habitats, lost elsewhere, which have survived. There are several kinds of important lowland habitat including valley bogs, alder carr, wet heaths, dry heaths and deciduous woodland. The area contains a profusion of rare wildlife, including the New Forest cicada, the only cicada native to Great Britain, although the last unconfirmed sighting was in 2000. The wet heaths are important for rare plants, such as marsh gentian and marsh clubmoss and other important species include the wild gladiolus.
Several species of sundew are found, as well as many unusual insect species, including the southern damselfly, large marsh grasshopper and the mole cricket, all rare in Britain. The Forest is an important stronghold for a rich variety of fungi, and although these have been heavily gathered in the past, there are control measures now in place to manage this.