Phylogeny of Madagascan Bulbophyllum (Orchidaceae)

Madagascar and the Mascarenes are known to harbour a unique fauna and flora, being the result of long isolation and a northward drift permitting the survival of frost-sensitive floras. Through human influence, environmental conditions in the region have been substantially altered. This is a still ongoing process. Therefore, there is an urgent need to study the remaining patches of primary (and secondary) vegetation, as they provide an ideal basis to trace back and understand evolutionary patterns. Best suited to investigate evolutionary mechanisms are plant groups having undergone intensive speciation on Madagascar, such as the huge pantropical genus Bulbophyllum (Orchidaceae) with nearly 200 species described for Madagascar, c. 98% of which are endemic. The project proposed primarily aims at a phylogenetic and biogeographic analysis of the Madagascan and Mascarenes species of Bulbophyllum, taking current and historical data into account. The project proposes to apply three different techniques to determine whether main speciation bursts correlate with climatological, geological or ecological events. First, main clades of closely related species will be identified and dated using phylogenetic analyses of DNA sequences and calibrations by vicariance. Secondly, analyses of distribution patterns using GIS will be performed to identify species-rich areas. Finally, possible correlations between main speciation events and climate, geology and ecological parameters will be investigated using phylogenetic-contrast analyses. The results will constitute an important evaluation of a major species-rich group of plants and provide a basis for designing areas deserving nature protection on Madagascar. The project is integrated in an actual worldwide collaborative approach to study the taxonomy, systematics and phylogeny of subtribe Bulbophyllinae and the genus Bulbophyllum (e.g., as part of research related to CITES implementation, or to get a better understanding of the tribal and infrageneric relationships). The data obtained in the project (species accounts and distribution patterns, phylogeny, threats, protection strategies) will also be valuable contributions to different targets of the Global Strategy for Plant Conservation (GSPC) adopted 2002 by the Convention on Biodiversity (CBD).

Madagascar and the Mascarenes are known to harbour a unique fauna and Flora, being the result of long isolation and a northward drift permitting the survival of Frost-sensitive floras. Through human influence, environmental conditions in the region have been substantially altered. This is a still ongoing process. Therefore, there is an urgent need to study the remaining patches of primary (and secondary) vegetation, as they provide an ideal basis to trace back and understand evolutionary patterns. Best suited to investigate evolutionary mechanisms are plant groups having undergone intensive speciation an Madagascar, such as the huge pantropical genus Bulbophyllum (Orchidaceae) with nearly 200 species described for Madagascar, c. 98% of which are endemic. The project proposed primarily aims at a phylogenetic and biogeographic analysis of the Madagascan and Mascarenes species of Bulbophyllum, taking current and historical data into account. The project proposes to apply three different techniques to determine whether main speciation bursts correlate with climatological, geological or ecological events. First, main clades of closely related species will be identified and dated using phylogenetic analyses of DNA sequences and calibrations by vicariance. Secondly, analyses of distribution patterns using GIS will be performed to identify species-rich areas. Finally, possible correlations between main speciation events and climate, geology and ecological parameters will be investigated using phylogenetic-contrast analyses. The results will constitute an important evaluation of a major species-rich group of plants and provide a basis for designing areas deserving nature protection an Madagascar. The project is integrated in an actual worldwide collaborative approach to study the taxonomy, systematics and phylogeny of subtribe Bulbophyllinae and the genus Bulbophyllum (e.g., as part of research related to CITES implementation, or to get a better understanding of the tribal and infrageneric relationships). The data obtained in the project (species accounts and distribution patterns, phylogeny, threats, protection strategies) will also be valuable contributions to different targets of the Global Strategy for Plant Conservation (GSPC) adopted 2002 by the Convention an Biodiversity (CBD).