The island syndrome in plants on New Zealand’s outlying islands: a review

The island syndrome is defined as a suite of predictable and consistent differences between island and mainland organisms. In seed plants, much of what we know about the island syndrome comes from work in the Southwest Pacific, which is comprised of the three main islands of New Zealand and ten surrounding archipelagos. These surrounding archipelagos are all remote and relatively small. They were never connected to another landmass and their floras are derived by overwater dispersal, mostly from the main islands of New Zealand, making them an ideal system for the study of island evolution. In this review, we summarise work on the island syndrome conducted on New Zealand’s outlying islands, establish whether these findings are in line with global patterns of island biology or whether they are unique to this region, and propose directions for future research.