Summer Activity Patterns of Antarctic and High Alpine Lichendominated Biological Soil Crusts—Similar But Different?

ABSTRACT

Biological soil crusts (BSCs) are small-scale communities of lichens, mosses, algae, and cyanobacteria that cover much of the surface area in regions where vascular plant growth is restricted due to harsh environmental conditions, such as perpetually ice-free areas in terrestrial Antarctic environments and alpine areas above the tree line. To our knowledge, none of the available studies provides a direct Antarctic-alpine comparison of BSC activity periods and the water use, both key traits to understand their physiological behavior and therefore related growth and fitness. Here, activity patterns and water relations were studied at two sites, one in continental Antarctica (Garwood Valley 78°S) and one in the High Alps of Austria (Hochtor, Großglockner 2350m). BSCs in continental Antarctica were only rarely active, and if so, then during melt after snowfalls and by fog. In the Austrian Alps, BSCs were continuously active and additionally activated by rainfall, fog, and dew. Consequently, high alpine BSCs can be expected to have much higher photosynthetic productivity supporting higher growth rates than the same functional vegetation unit has in continental Antarctica.

Acknowledgments

This research is part of the New Zealand Terrestrial Antarctic Biocomplexity Survey (NZTABS) and was supported by the New Zealand Foundation for Research Science and Technology (Grant UOWX0710, “Understanding, valuing and protecting Antarctica's unique terrestrial ecosystems: predicting biocomplexity in Dry Valley ecosystems”). Antarctica New Zealand is thanked for providing logistics both for the research in Antarctica and movements to Antarctica. Permits: sampling, entry into protected areas and equipment deployment were approved by the New Zealand authorities. Part of the research was funded by the ERA-Net BiodivERsA program,“Improved appreciation of the functioning and importance of biological soil crusts in Europe: the Soil Crust International Project (SCIN)” as part of the 2010–2011 BiodivERsA joint call. Hans Reichenberger, Laura Williams, Martin Schaaf, and Katharina Schneider are thanked for field and lab assistance.