Biodiversity and molecular systematics of subaerial algae from Africa and the Neotropics

Algae are a large and diverse group of photosynthetic organisms that range in size from microscopic unicellular to multicellular forms. They usually inhabit marine and freshwater habitats. However, some are terrestrial and are capable of living in soil or above the soil surface (subaerial). Tropical rainforests, with humid climate and diverse habitats, offer phycologists with a rich field for biodiversity exploration. In the past, algae in these environments have been the objective of many studies. However, algae from the African Tropical rainforest have been greatly overlooked. This investigation is targeting the biodiversity of subaerial algae from an African tropical rainforest in Gabon (Africa) as well as a Neotropical forest in Panama (Central America). During this investigation biodiversity studies were based on traditional assessments as well as state of the art technology such as metagenomic approaches.;In this study, morphology based and molecular phylogenetic protocols have been integrated to elucidate the biodiversity and systematics of the subaerial green algal order Trentepohliales from Gabon, Africa. Based on morphological observations 14 species of Trentepohlia and Printzina (belonging to the order Trentepohliales) were found to occur in Gabon (six were newly recorded for the continent). Molecular phylogenetics of the Trentepohliales from Africa suggested that the genera Trentepohlia and Printzina are not monophyletic lineages. These results also suggested that a taxonomic reassessment of the Trentepohliales is necessary.;The African subaerial algal biodiversity was assessed using a novel metagenomic approach at a broader taxonomic level. Results of this approach suggest that the African rainforest is home to green algal (Chlorophyta), cyanobacteria, and diatoms (Sramenopiles) taxa. Finally, Panamanian subaerial diversity was also evaluated using a metagenomic approach with an ecological application: the biodiversity of the epiphytic flora was compared in four different tree heights as well as the potential effect of the orientation (East versus West). Results of this investigation indicate that the distribution of the algal diversity in terms of major groups was essentially following a similar pattern along the vertical gradient in the forest canopy. In contrast, the distribution of algal groups and specialized taxa was dissimilar between Western and Eastern faces of trees.