Species Invasions Exceed Extinctions on Islands Worldwide: A Comparative Study of Plants and Birds

  title={Species Invasions Exceed Extinctions on Islands Worldwide: A Comparative Study of Plants and Birds},
  author={Dov F. Sax and Steven D. Gaines and James H. Brown},
  journal={The American Naturalist},
  pages={766 - 783}
Species richness is decreasing at a global scale. At subglobal scales, that is, within any defined area less extensive than the globe, species richness will increase when the number of nonnative species becoming naturalized is greater than the number of native species becoming extinct. Determining whether this has occurred is usually difficult because detailed records of species extinctions and naturalizations are rare; these records often exist, however, for oceanic islands. Here we show that… 
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    Proceedings of the National Academy of Sciences
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