TY - JOUR

T1 - Gradient Studies Reveal the True Drivers of Extreme Life in the Atacama Desert

AU - Boy, D.

AU - Moeller, R.

AU - Sauheitl, L.

AU - Schaarschmidt, F.

AU - Rapp, S.

AU - Brink, L.

AU - Gschwendtner, S.

AU - Borquez, R. Godoy

AU - Matus, FranciscoJ

AU - Horn, M. A.

AU - Guggenberger, G.

AU - Boy, J.

N1 - Funding Information: The authors wish to thank the German Research Foundation (DFG) for funding of this study in the frame of the German‐Chilean joint priority research project SPP 1803 (BO3741/4‐1). We received invaluable support in the laboratory from Ulrike Pieper, Anne Herwig, Jan‐Philip Dieck, Talitha Henneking and several other wonderful collegues for whose help we are very grateful. R.M. was supported by the DLR grant FuE‐Projekt “ISS LIFE” (Programm RF‐FuW, Teilprogramm 475). We thank the anonymous reviewers for their very helpful advice. Open access funding enabled and organized by Projekt DEAL. EarthShape

PY - 2022/3/4

Y1 - 2022/3/4

N2 - Studies of hyper-arid sites contribute to our understanding on how life adapted to extreme conditions. They are often used to further deduce implications for extraterrestrial biology by the so-called analogue site-approach. The Atacama Desert, Chile, is one of the most prominent analogue sites despite its neighboring productive ecosystems due to its hyper-aridity and geochemical features resembling Martian environments. We hypothesize that many drivers of extremophile life in analogue sites are only mistakenly attributed to aridity alone, thus obscuring a clear view of the far more complex process interactions originating in nearby earthly ecosystems. To test this, we investigated 54 soil profiles up to 60 cm of soil depth along of four transects in the Atacama Desert, either running parallel (S-N) or perpendicular (W-E) to the Andes. Our objective was to reveal the processes controlling the formation of soil organic carbon (SOC) as the most reliable proxy for microbial life in order to understand the boundary conditions of life in extreme habitats. Further, we aimed at identifying analogue sites as uncompromised as possible by external influences of for example, vegetated or marine ecosystems. We found a mixture of influences driving habitable conditions on gradients perpendicular to the Andes, for example, fog and precipitation scavenging caused by altitudinal variations and differing proximity to the Pacific Ocean, while transects parallel to the Andes were much less biased by external factors. Our results show that studies on life under extreme conditions should clarify the explanatory strength of the investigated factors by a gradient study approach.

AB - Studies of hyper-arid sites contribute to our understanding on how life adapted to extreme conditions. They are often used to further deduce implications for extraterrestrial biology by the so-called analogue site-approach. The Atacama Desert, Chile, is one of the most prominent analogue sites despite its neighboring productive ecosystems due to its hyper-aridity and geochemical features resembling Martian environments. We hypothesize that many drivers of extremophile life in analogue sites are only mistakenly attributed to aridity alone, thus obscuring a clear view of the far more complex process interactions originating in nearby earthly ecosystems. To test this, we investigated 54 soil profiles up to 60 cm of soil depth along of four transects in the Atacama Desert, either running parallel (S-N) or perpendicular (W-E) to the Andes. Our objective was to reveal the processes controlling the formation of soil organic carbon (SOC) as the most reliable proxy for microbial life in order to understand the boundary conditions of life in extreme habitats. Further, we aimed at identifying analogue sites as uncompromised as possible by external influences of for example, vegetated or marine ecosystems. We found a mixture of influences driving habitable conditions on gradients perpendicular to the Andes, for example, fog and precipitation scavenging caused by altitudinal variations and differing proximity to the Pacific Ocean, while transects parallel to the Andes were much less biased by external factors. Our results show that studies on life under extreme conditions should clarify the explanatory strength of the investigated factors by a gradient study approach.

KW - Atacama

KW - Wüste

KW - SOC

KW - Trockenheit

KW - Habitabilität

UR - http://www.scopus.com/inward/record.url?scp=85127321727&partnerID=8YFLogxK

U2 - 10.1029/2021jg006714

DO - 10.1029/2021jg006714

M3 - Article

VL - 127

JO - Journal of Geophysical Research: Biogeosciences

JF - Journal of Geophysical Research: Biogeosciences

SN - 2169-8953

IS - 3

M1 - e2021JG006714

ER -