Exploration of the diversity of tree ferns (Cyatheaceae, Dicksoniaceae - Polypodiopsida) along two elevational gradients in Indonesian New Guinea

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The tree ferns of the families Cyatheaceae and Dicksoniaceae comprise the largest living ferns. Fragmentary collections and insufficient documentation of their habit have rendered their taxonomy a still unresolved problem Both families have a geologic history dating back to the early Mesozoic but also an impressive extant diversity, which makes them perfect objects to explore general patterns of phylogeography and the mechanisms behind recent adaptive radiations. In existing phylogenies many crucial groups are underrepresented. New Guinea has a diverse tropical flora rich in endemics but is still widely unexplored. The proposed project aims to get a representative collection of New Guinean Cyatheaceae and Dicksoniaceae to test current taxonomic and phylogenetic hypotheses. In particular, we will look for basal members of Cyathea, which are presumed to occur on the island, in order to get a better resolution and dating of the basal split the between the neotropical and paleotropical clade in this genus. Further it will be tested if the New Guinean Cyatheaceae have experienced a similar recent radiation burst as in the Andes and on Madagascar. Finally, we will look if the relict genus Dicksonia is represented on the island with neo- or paleoendemics.