Water is the defining feature of the habitable Earth; it is essential for all life as we know it. Evolution and maintenance of life in extremely water limited environments, which cover significant portions of the Earth, is not well understood. Akin to life, water-driven processes leave unique marks on the Earth’s surface. Mars is the only other planet currently known to bear the marks of water-driven surface processes, albeit fossil and of great age. The slow biotic and abiotic surface processes that may operate even in the virtual absence of liquid water are still essentially unknown. What is evident is that transient episodes of increased water availability can leave long lasting traces in extremely water limited environments. Intriguingly, those traces of bursts in Earth surface evolution have rarely been related to bursts in biological colonization/evolution, and vice versa, although both relate to the same trigger: water.

The objective of this session is to showcase research on the mutual evolutionary relationships between Earth surface processes and biota in arid to hyper-arid systems, where both biota and Earth surface process are severely and predominantly limited by the availability of water (rather than by extreme temperatures).
Solicited topics include (not exhaustive):
• fingerprints of biological activity at the (water) limit of the habitable Earth
• surface processes operating in the (virtual) absence of liquid water on Earth or extraterrestrial analogues (e.g. Mars)
• thresholds for biological colonization and concurrent fluvial transformation of landscapes
• tipping point(s) of biotically and abiotically controlled Earth surface systems
• chronometric and spatial information on the colonization and radiation of biota
terrestrial climatic records of (hyper-) arid regions on Earth

Co-organized as BG7.4/CL4.38/PS4.7
Convener: Tibor J. Dunai | Co-conveners: Eduardo Campos, Cristina Dorador, Claudia Knief, Laura Evenstar
| Wed, 10 Apr, 08:30–12:30, 14:00–15:45
Room 0.31
| Attendance Thu, 11 Apr, 10:45–12:30
Hall X2

Wednesday, 10 April 2019 | Room 0.31

Chairperson: Laura Evenstar
08:30–08:45 |
Volker Wennrich, Julia Diederich, Emma Fernandez Galego, Benedikt Ritter, Dominik Brill, Alicia Utande, Stefan Buske, Barbara Blanco Arrue, Pritam Yogeshwar, Christian Rolf, Stephanie Scheidt, Catalina Gebhardt, Roberto Bao, Eduardo Campos Sepúlveda, Tibor Dunai, and Martin Melles
08:45–09:00 |
Paulina Vásquez, Fernando Sepúlveda, and Andres Quezada
09:00–09:15 |
Benedikt Ritter, Julia Diederich, Finlay M. Stuart, Steven A. Binnie, Andreas Bolten, and Tibor J. Dunai
09:15–09:30 |
Simon Matthias May, Dirk Hoffmeister, Dennis Wolf, and Olaf Bubenzer
09:45–10:00 |
Andres Quezada, Nicolas Blanco, Paulina Vasquez, and Fernando Sepulveda
10:00–10:15 |
Melanie Bartz, Mathieu Duval, Janek Walk, Dominik Brill, Anja Zander, Georgina E. King, Georg Stauch, Frank Lehmkuhl, and Helmut Brückner
Coffee break
Chairperson: Eduardo Campos
10:45–11:00 |
Joel Mohren, Steven Binnie, Damián Lopez, Benedikt Ritter, and Tibor Dunai
11:00–11:15 |
Steven Binnie, Klaus Reicherter, Pia Victor, Gabriel González, Ariane Binnie, Karin Niemann, Jorien van der Wal, and Jana Mittelstädt
11:15–11:30 |
Jan H. Schween, Dirk Hoffmeister, and Ulrich Löhnert
11:30–11:45 |
Mark Reyers, Christoph Böhm, Yaping Shao, Ulrich Löhnert, and Susanne Crewell
11:45–12:00 |
Christoph Böhm, Mark Reyers, Jan Schween, Ulrich Löhnert, and Susanne Crewell
12:00–12:15 |
| Highlight
Ramona Mörchen, Eva Lehndorff, Barbara Fuentes, Franko Arenas, Ghazal Moradi, Erwin Klumpp, Roland Bol, and Wulf Amelung
12:15–12:30 |
Barbara Fuentes, Alessandra Choque, Francisco Gómez, Franko Arenas, Francisco Remonsellez, Ghazal Moradi, and Roland Bol
Lunch break
Chairperson: Claudia Knief
14:00–14:15 |
Franko Arenas Díaz, Barbara Fuentes, David L. Jones, and Roland Bol
14:15–14:30 |
Felix Merklinger, Federico Luebert, Doerte Harpke, Tim Boehnert, Alexandra Stoll, Andrea Jaeschke, Marcus Koch, Claudia Schuette, Frank Blattner, Maximilian Weigend, Yichen Zheng, Thomas Wiehe, and Dietmar Quandt
14:30–14:45 |
Reinhard Predel, Julia Oly, and Álvaro Zúñiga-Reinoso
14:45–15:00 |
Peter Heger, Lapo Ragionieri, Reinhard Predel, and Thomas Wiehe
15:00–15:15 |
Hartmut Arndt, Sarah Carduck, Alexandra Rybarski, Sabine Schiwitza, and Frank Nitsche
15:30–15:45 |
Analysis of evolutionary processes within the placidid stramenopile flagellates in the Atacama Desert
Alexandra Rybarski, Frank Nitsche, and Hartmut Arndt