TY - JOUR

T1 - Nutrient-limited subarctic caves harbour more diverse and complex bacterial communities than their surface soil

AU - Reboleira, Ana Sofia

AU - Bodawatta, Kasun H.

AU - Ravn, Nynne M. R.

AU - Lauritzen, Stein-Erik

AU - Skoglund, Rannveig Øvrevik

AU - Poulsen, Michael

AU - Michelsen, Anders

AU - Jønsson, Knud Andreas

N1 - Funding Information: This work is supported by a research Grants (15471 and 15560) from the Villum Fonden, by the Carlsberg Foundation (CF17-0248), and by Portuguese National Funds through “Fundação para a Ciência e Tecnologia” (FCT) within the cE3c Unit funding UIDB/00329/2020. Funding Information: The “Elgfjellet Project” was financed through the Lomsdal-Visten National Park management, and we thank director Torhild Lamo and Carl Norberg for their total support. The MSc students (Thea Krossøy, Lene Bukholm, Linett Jenssen, Terje Remmen and Markus Torstad) indirectly contributed to the project through their geomorphological work. We are grateful to Thomas Pape (Diptera), Reinhardt Kristensen (Tardigrada), Alexey Solodovnikov (Staphylinidae) and Gustavo Hormiga (Araneae) for confirming species identification. Publisher Copyright: © 2022, The Author(s).

PY - 2022

Y1 - 2022

N2 - Background: Subarctic regions are particularly vulnerable to climate change, yet little is known about nutrient availability and biodiversity of their cave ecosystems. Such knowledge is crucial for predicting the vulnerability of these ecosystems to consequences of climate change. Thus, to improve our understanding of life in these habitats, we characterized environmental variables, as well as bacterial and invertebrate communities of six subarctic caves in Northern Norway. Results: Only a minuscule diversity of surface-adapted invertebrates were found in these caves. However, the bacterial communities in caves were compositionally different, more diverse and more complex than the nutrient-richer surface soil. Cave soil microbiomes were less variable between caves than between surface communities in the same area, suggesting that the stable cave environments with tougher conditions drive the uniform microbial communities. We also observed only a small proportion of cave bacterial genera originating from the surface, indicating unique cave-adapted microbial communities. Increased diversity within caves may stem from higher niche specialization and levels of interdependencies for nutrient cycling among bacterial taxa in these oligotrophic environments. Conclusions: Taken together this suggest that environmental changes, e.g., faster melting of snow as a result of global warming that could alter nutrient influx, can have a detrimental impact on interactions and dependencies of these complex communities. This comparative exploration of cave and surface microbiomes also lays the foundation to further investigate the long-term environmental variables that shape the biodiversity of these vulnerable ecosystems.

AB - Background: Subarctic regions are particularly vulnerable to climate change, yet little is known about nutrient availability and biodiversity of their cave ecosystems. Such knowledge is crucial for predicting the vulnerability of these ecosystems to consequences of climate change. Thus, to improve our understanding of life in these habitats, we characterized environmental variables, as well as bacterial and invertebrate communities of six subarctic caves in Northern Norway. Results: Only a minuscule diversity of surface-adapted invertebrates were found in these caves. However, the bacterial communities in caves were compositionally different, more diverse and more complex than the nutrient-richer surface soil. Cave soil microbiomes were less variable between caves than between surface communities in the same area, suggesting that the stable cave environments with tougher conditions drive the uniform microbial communities. We also observed only a small proportion of cave bacterial genera originating from the surface, indicating unique cave-adapted microbial communities. Increased diversity within caves may stem from higher niche specialization and levels of interdependencies for nutrient cycling among bacterial taxa in these oligotrophic environments. Conclusions: Taken together this suggest that environmental changes, e.g., faster melting of snow as a result of global warming that could alter nutrient influx, can have a detrimental impact on interactions and dependencies of these complex communities. This comparative exploration of cave and surface microbiomes also lays the foundation to further investigate the long-term environmental variables that shape the biodiversity of these vulnerable ecosystems.

KW - Cave microbiomes

KW - Microbial co-occurrence networks

KW - Subarctic ecosystems

KW - Subsurface

KW - Subterranean ecosystems

U2 - 10.1186/s40793-022-00435-z

DO - 10.1186/s40793-022-00435-z

M3 - Journal article

C2 - 35941623

AN - SCOPUS:85135564555

VL - 17

JO - Environmental Microbiomes

JF - Environmental Microbiomes

SN - 1944-3277

M1 - 41

ER -