Skip to main content
Research article - Peer-reviewed, 2022

Contribution of soil algae to the global carbon cycle

Jassey, Vincent E. J.; Walcker, Romain; Kardol, Paul; Geisen, Stefan; Heger, Thierry; Lamentowicz, Mariusz; Hamard, Samuel; Lara, Enrique


Soil photoautotrophic prokaryotes and micro-eukaryotes - known as soil algae - are, together with heterotrophic microorganisms, a constitutive part of the microbiome in surface soils. Similar to plants, they fix atmospheric carbon (C) through photosynthesis for their own growth, yet their contribution to global and regional biogeochemical C cycling still remains quantitatively elusive. Here, we compiled an extensive dataset on soil algae to generate a better understanding of their distribution across biomes and predict their productivity at a global scale by means of machine learning modelling. We found that, on average, (5.5 +/- 3.4) x 10(6) algae inhabit each gram of surface soil. Soil algal abundance especially peaked in acidic, moist and vegetated soils. We estimate that, globally, soil algae take up around 3.6 Pg C per year, which corresponds to c. 6% of the net primary production of terrestrial vegetation. We demonstrate that the C fixed by soil algae is crucial to the global C cycle and should be integrated into land-based efforts to mitigate C emissions.


biogeography; microbial photosynthesis; net primary productivity (NPP); photoautotrophs; soil carbon (C) cycle; soil microbiome

Published in

New Phytologist
2022, volume: 234, number: 1, pages: 64-76
Publisher: WILEY

Authors' information

Jassey, Vincent E. J.
Universite Toulouse III - Paul Sabatier
Walcker, Romain
Universite de Toulouse
Swedish University of Agricultural Sciences, Department of Forest Ecology and Management
Geisen, Stefan
Wageningen University and Research
Heger, Thierry
University of Applied Sciences and Arts Western Switzerland (HES-SO)
Lamentowicz, Mariusz
Adam Mickiewicz University
Hamard, Samuel
Universite Toulouse III - Paul Sabatier
Lara, Enrique
CSIC - Real Jardin Botanico de Madrid

UKÄ Subject classification

Soil Science

Publication Identifiers


URI (permanent link to this page)