Biogeographic congruence in the South Pacific

Abstract

Ever since J. D. Hooker's famous 'Introductory Essay' to Flora NOVE-Zelandise, a classical problem in biogeography has been to give a casual explanation of southern hemisphere distribution patterns. An attempt is made to see whether the cladograms for the circum-Pacific areas (South America, New Zealand, Tasmania and Australia) are congruent. The area cladograms are derived from Nothofagus (Fagacae), Embothriinae (Protaceae), Oreobolus (Cyperaceae), Cyttaria (Helotiales) and Eriococcidae (Homoptera). The resulting general area cladogram showing southern South America as the sister-area to New Zealand, south-eastern Australia and Tasmania, and Tasmania plus south-eastern Australia as sister-areas to New Zealand are compared with different geological hypotheses for the area. The biological area cladogram is shown to be congruent with widely different geological hypotheses.