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

Cyatheaceae和Dicksoniaceae的树蕨是现存最大的蕨类植物。这两个科的地质历史可以追溯到中生代早期，但也有令人印象深刻的现存多样性，这使它们成为探索系统地理学一般模式和最近适应性辐射背后机制的完美对象。在现有的系统发育中，许多关键群体的代表性不足。新几内亚拥有丰富的热带植物群，但仍未被广泛开发。该项目旨在收集新几内亚Cyatheaceae和Dicksoniaceae的代表性标本，以检验目前的分类和系统发育假说。特别是，我们将寻找被认为存在于岛上的Cyathea的基部成员，以便更好地确定该属中新热带和古热带分支之间的基部分裂。此外，还将测试新几内亚Cyatheaceae是否经历过与安第斯山脉和马达加斯加相似的近期辐射爆发。最后，我们将看看岛上是否有新或古地方性的Dicksonia属。

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.