Trophic Selective Pressures Organize the Composition of Endolithic Microbial Communities From Global Deserts

Evan B. Qu, Chris R. Omelon, Aharon Oren, Victoria Meslier, Don A. Cowan, Gillian Maggs-Kölling, Jocelyne DiRuggiero*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


Studies of microbial biogeography are often convoluted by extremely high diversity and differences in microenvironmental factors such as pH and nutrient availability. Desert endolithic (inside rock) communities are relatively simple ecosystems that can serve as a tractable model for investigating long-range biogeographic effects on microbial communities. We conducted a comprehensive survey of endolithic sandstones using high-throughput marker gene sequencing to characterize global patterns of diversity in endolithic microbial communities. We also tested a range of abiotic variables in order to investigate the factors that drive community assembly at various trophic levels. Macroclimate was found to be the primary driver of endolithic community composition, with the most striking difference witnessed between hot and polar deserts. This difference was largely attributable to the specialization of prokaryotic and eukaryotic primary producers to different climate conditions. On a regional scale, microclimate and properties of the rock substrate were found to influence community assembly, although to a lesser degree than global hot versus polar conditions. We found new evidence that the factors driving endolithic community assembly differ between trophic levels. While phototrophic taxa, mostly oxygenic photosynthesizers, were rigorously selected for among different sites, heterotrophic taxa were more cosmopolitan, suggesting that stochasticity plays a larger role in heterotroph assembly. This study is the first to uncover the global drivers of desert endolithic diversity using high-throughput sequencing. We demonstrate that phototrophs and heterotrophs in the endolithic community assemble under different stochastic and deterministic influences, emphasizing the need for studies of microorganisms in context of their functional niche in the community.

Original languageAmerican English
Article number2952
JournalFrontiers in Microbiology
StatePublished - 8 Jan 2020

Bibliographical note

Publisher Copyright:
© Copyright © 2020 Qu, Omelon, Oren, Meslier, Cowan, Maggs-Kölling and DiRuggiero.


  • biogeography
  • desert
  • endolithic
  • microbial assembly
  • trophic level
  • xerotolerant


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