Ecology and diversity of microbial phototrophs in biological soil crusts of Polar Regions

Abstract

Biological soil crusts (BSCs) are important components of semi-arid and arid environments and occupy a large area in Polar Regions. However, their ecological functions and the diversity of major organisms are still ambiguous. Given that rapid climate change is of particular significance and the current warming is already attributed to small variations on the Earth, it is important to obtain a more comprehensive picture about the environment to predict its changes. Moreover, climate change is faster and more severe in Polar Regions than in other parts of the world. In this context, the thesis is focused on the community structure of microbial phototrophs and their ecological functions in BSCs of the Arctic (Central Svalbard) and Antarctica (Dronning Maud Land). Combining molecular and morphological techniques we described cyanobacterial community composition in BSCs and its changes along the gradient of soil crust development. Moreover, we showed how the different stages of soil crust development (from poorly-developed to well-developed) influence photosynthetic and nitrogenase activities associated with the phototrophic community.