Niche Conservatism Drives the Elevational Diversity Gradient in Major Groups of Free-Living Soil Unicellular Eukaryotes

Fernández, Leonardo D.; Seppey, Christophe V. W.; Singer, David; Fournier, Bertrand; Tatti, Dylan; Mitchell, Edward A. D.; Lara, Enrique (2021). Niche Conservatism Drives the Elevational Diversity Gradient in Major Groups of Free-Living Soil Unicellular Eukaryotes Microbial Ecology, 83(2), pp. 459-469. Springer 10.1007/s00248-021-01771-2

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Ancestral adaptations to tropical-like climates drive most multicellular biogeography and macroecology. Observational studies suggest that this niche conservatism could also be shaping unicellular biogeography and macroecology, although evidence is limited to Acidobacteria and testate amoebae. We tracked the phylogenetic signal of this niche conservatism in far related and functionally contrasted groups of common soil protists (Bacillariophyta, Cercomonadida, Ciliophora, Euglyphida and Kinetoplastida) along a humid but increasingly cold elevational gradient in Switzerland. Protist diversity decreased, and the size of the geographic ranges of taxa increased with elevation and associated decreasing temperature (climate), which is consistent with a macroecological pattern known as the Rapoport effect. Bacillariophyta exhibited phylogenetically overdispersed communities assembled by competitive exclusion of closely related taxa with shared (conserved) niches. By contrast, Cercomonadida, Ciliophora, Euglyphida and Kinetoplastida exhibited phylogenetically clustered communities assembled by habitat filtering, revealing the coexistence of closely related taxa with shared (conserved) adaptations to cope with the humid but temperate to cold climate of the study site. Phylobetadiversity revealed that soil protists exhibit a strong phylogenetic turnover among elevational sites, suggesting that most taxa have evolutionary constraints that prevent them from colonizing the colder and higher sites of the elevation gradient. Our results suggest that evolutionary constraints determine how soil protists colonize climates departing from warm and humid conditions. We posit that these evolutionary constraints are linked to an ancestral adaptation to tropical-like climates, which limits their survival in exceedingly cold sites. This niche conservatism possibly drives their biogeography and macroecology along latitudinal and altitudinal climatic gradients.

Item Type:	Journal Article (Original Article)
Division/Institute:	School of Agricultural, Forest and Food Sciences HAFL School of Agricultural, Forest and Food Sciences HAFL > Agriculture School of Agricultural, Forest and Food Sciences HAFL > Agriculture > Soils and Geoinformation
Name:	Fernández, Leonardo D.; Seppey, Christophe V. W.; Singer, David; Fournier, Bertrand; Tatti, Dylan; Mitchell, Edward A. D. and Lara, Enrique
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > QK Botany Q Science > QL Zoology S Agriculture > SB Plant culture
ISSN:	0095-3628
Publisher:	Springer
Language:	English
Submitter:	Simon Lutz
Date Deposited:	02 Jul 2021 11:11
Last Modified:	06 Mar 2022 01:34
Publisher DOI:	10.1007/s00248-021-01771-2
Uncontrolled Keywords:	Biogeography and macroecology · Cercomonadids · Ciliates · Diatoms · Kinetoplastids · Testate amoebae
ARBOR DOI:	10.24451/arbor.15083
URI:	https://arbor.bfh.ch/id/eprint/15083