Resistance, emigration, or adaptation? Phylogeography and ecology of European alpine plant species
Schneeweiss, Gerald M. .
Phylogeny and evolution of alpine species in the European endemic Phyteuma (Campanulaceae).
The European endemic Phyteuma comprises ca. 20 species morphologically well characterized by their peculiar flower morphology suggesting monophyly of this group. Phyteuma occurs in different habitats ranging from lowland woodlands to alpine pastures and subnival pioneer communities, which renders it a very good system in which to investigate the evolution of habitat preferences. In particular, the hypothesis of the evolution of alpine groups from woodland ancestors can be tested. A sound molecular phylogenetic hypothesis has been established using nuclear ITS and plastid trnL-F-sequences (intron and spacer) including also a wide array of outgroup taxa. The molecular results suggest the monotypic Physoplexis, an endemic of the southeastern Alps, as sister group to Phyteuma. The latter falls into two well-supported monophyletic groups corresponding to previously recognized sections. Species of sect. Phyteuma have elongated spike-like inflorescences without an involucrum, while those of sect. Capitata have capitulum-like inflorescences with an involucrum. These two groups differ markedly in their habitat preferences. Species of sect. Phyteuma are mostly confined to habitats below the tree-line (woodlands, subalpine meadows) with only weak tendencies into alpine habitats in Ph. pyrenaicum, while the majority of species of sect. Capitata is restricted to alpine to subnival habitats. Using different methods of ancestral character states reconstruction (maximum parsimony, maximum likelihood) and several habitat coding schemes, the ancestor of Phyteuma is suggested to have been rather a non-alpine chasmophyte than a woodland species. Finally, divergence times of species with contrasting habitat preferences were estimated in order to attempt to correlate their divergent evolution with paleogeographical and –climatological events.
1 - University of Vienna, Institute for Botany, Department of Plant Biogeography, Rennweg 14, Vienna, A 1030, Austria
Presentation Type: Symposium
Location: Ballroom 2 (Cliff Lodge)
Date: Wednesday, August 4th, 2004
Time: 11:00 AM