Environmental predictors of pre-European deforestation on Pacific islands

• Published in: Nature 2004-09, Vol.431 (7007), p.443-446
• Main Authors: Rolett, B, Diamond, J
• Format: Article
• Language: English
• Subjects: Altitude; Animal, plant and microbial ecology; Animals; Anthozoa; anthropogenic activities; Applied ecology; Biological and medical sciences; Comparative analysis; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; Deforestation; Dust; Ecosystem; edaphic factors; Environmental factors; Europe - ethnology; forest ecology; forest trees; Fundamental and applied biological sciences. Psychology; geographical variation; Geography; Humanities and Social Sciences; Introduced species; Islands; letter; multidisciplinary; Pacific Islands - ethnology; Pacific Ocean; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Plant species introduction; Population Dynamics; Rain; Science; Science (multidisciplinary); Soil - analysis; Statistical analysis; Trees - physiology; Volcanic Eruptions; weather
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature02801

Some Pacific island societies, such as those of Easter Island and Mangareva, inadvertently contributed to their own collapse by causing massive deforestation. Others retained forest cover and survived. How can those fateful differences be explained? Although the answers undoubtedly involve both different cultural responses of peoples and different susceptibilities of environments, how can one determine which environmental factors predispose towards deforestation and which towards replacement of native trees with useful introduced tree species? Here we code European-contact conditions and nine environmental variables for 81 sites on 69 Pacific islands from Yap in the west to Easter in the east, and from Hawaii in the north to New Zealand in the south. We thereby detect statistical decreases in deforestation and/or forest replacement with island rainfall, elevation, area, volcanic ash fallout, Asian dust transport and makatea terrain (uplifted reef), and increases with latitude, age and isolation. Comparative analyses of deforestation therefore lend themselves to much more detailed interpretations than previously possible. These results might be relevant to similar deforestation-associated collapses (for example, Fertile Crescent, Maya and Anasazi) or the lack thereof (Japan and highland New Guinea) elsewhere in the world.