Enumerating soil biodiversity
Edited by Diana Wall, Colorado State University, Fort Colliins, CO; received March 21, 2023; accepted July 2, 2023
Commentary
August 30, 2023
Significance
Soil organisms mediate unique functions we rely on for food, fiber, and human and planetary health. Despite the significance of soil life, we lack a quantitative estimate of soil biodiversity, making it challenging to advocate for the importance of protecting, preserving, and restoring soil life. Here, we show that soil is likely home to 59% of life including everything from microbes to mammals, making it the singular most biodiverse habitat on Earth. Our enumeration can enable stakeholders to more quantitatively advocate for soils in the face of the biodiversity crisis.
Abstract
Soil is an immense habitat for diverse organisms across the tree of life, but just how many organisms live in soil is surprisingly unknown. Previous efforts to enumerate soil biodiversity consider only certain types of organisms (e.g., animals) or report values for diverse groups without partitioning species that live in soil versus other habitats. Here, we reviewed the biodiversity literature to show that soil is likely home to 59 ± 15% of the species on Earth. We therefore estimate an approximately two times greater soil biodiversity than previous estimates, and we include representatives from the simplest (microbial) to most complex (mammals) organisms. Enchytraeidae have the greatest percentage of species in soil (98.6%), followed by fungi (90%), Plantae (85.5%), and Isoptera (84.2%). Our results demonstrate that soil is the most biodiverse singular habitat. By using this estimate of soil biodiversity, we can more accurately and quantitatively advocate for soil organismal conservation and restoration as a central goal of the Anthropocene.
Data, Materials, and Software Availability
All data and scripts associated with this manuscript are available in the following GitLab repository: https://gitlab.com/fungalecology/soil_biodiversity_review (115).
Acknowledgments
This research was funded by grants from the Swiss NSF awarded to MA (PZ00P3_208648) and MvdH (310030-188799). A portion of data were produced by the US Department of Energy Joint Genome Institute (https://ror.org/04xm1d337; operated under Contract No. DE-AC02-05CH11231) in collaboration with the user community. We would also like to thank Stefan Geisen and Joanne Emerson for helpful feedback on earlier versions of the manuscript. We thank Michael Dandley (www.michaeldandley.com) for designing and illustrating the soil organisms shown in Fig. 3 and Elena Havlicek for discussion and exchange.
Author contributions
M.A.A., S.F.B., and M.G.A.v.d.H. designed research; M.A.A. performed research; M.A.A. analyzed data; and M.A.A., S.F.B., and M.G.A.v.d.H. wrote the paper.
Competing interests
The authors declare no competing interest.
Supporting Information
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Cover image: Pictured is a crystal embedded in a hybrid organic–inorganic structure. Silvia Holler et al. simulated the conditions under which inorganic structures at hydrothermal vents may have promoted protocell formation by introducing decanol, an organic fatty alcohol, into an inorganic system. A diverse range of 3D architectures emerged upon the addition of decanol—at both microscales and macroscales. The structures supported the formation of simple protocellular entities, including vesicles. According to the authors, the integration of decanol and porous inorganic structures represents a potential mechanism for the emergence of protocellular systems in a prebiotic scenario. See the article by Holler et al., e2300491120. Image credit: Lorenzo Moschini and Antonella Motta (University of Trento, Trento, Italy).
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Copyright © 2023 the Author(s). Published by PNAS. This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Data, Materials, and Software Availability
All data and scripts associated with this manuscript are available in the following GitLab repository: https://gitlab.com/fungalecology/soil_biodiversity_review (115).
Submission history
Received: March 21, 2023
Accepted: July 2, 2023
Published online: August 7, 2023
Published in issue: August 15, 2023
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Acknowledgments
This research was funded by grants from the Swiss NSF awarded to MA (PZ00P3_208648) and MvdH (310030-188799). A portion of data were produced by the US Department of Energy Joint Genome Institute (https://ror.org/04xm1d337; operated under Contract No. DE-AC02-05CH11231) in collaboration with the user community. We would also like to thank Stefan Geisen and Joanne Emerson for helpful feedback on earlier versions of the manuscript. We thank Michael Dandley (www.michaeldandley.com) for designing and illustrating the soil organisms shown in Fig. 3 and Elena Havlicek for discussion and exchange.
Author Contributions
M.A.A., S.F.B., and M.G.A.v.d.H. designed research; M.A.A. performed research; M.A.A. analyzed data; and M.A.A., S.F.B., and M.G.A.v.d.H. wrote the paper.
Competing Interests
The authors declare no competing interest.
Notes
This article is a PNAS Direct Submission.
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