With the exception of the Bounty Islands which have no higher plants, the remaining islands, together with neighbouring Macquarie Island, constitute a Centre of Plant Diversity, and have the richest flora of all of the Subantarctic islands. The terrestrial flora comprises approximately 250 taxa, of which 35 are endemic to the region. The Auckland Islands alone have 233 vascular plants of which 196 are indigenous and six endemic. Thirty are classified as rare. The Auckland Islands have the southernmost forests in the region, dominated by Southern Rata Metrosideros umbellata and a flowering myrtle.
Tree ferns reach their southern limit here.
The Snares have extensive forests dominated by a tree daisy Olearia lyalli up to 5m high. There are no comparable forests on the Campbell and Antipodes Islands, though woody shrubs are present. Seaweed diversity is not as rich as on the mainland, but a new species of bull kelp Durvillaea has been identified from the Antipodes Islands. The fauna reflects the highly productive marine ecosystem which gives rise to a huge abundance and diversity of seabirds and marine mammals. Ten of the world's 24 species of albatross breed in the islands.