Journal Article

Cyanobacterial biocrust diversity in Mediterranean ecosystems along a latitudinal and climatic gradient

M. Ángeles Muñoz-Martín, Pilar Mateo, Itzel Becerra-Absalón, Elvira Perona, Lara Fernández-Valbuena, Ferran Garcia-Pichel

2019

Overview

Cyanobacteria are a key biotic component as primary producers in biocrusts, topsoil communities that have important roles in the functioning of drylands. Yet, major knowledge gaps exist regarding the composition of biocrust cyanobacterial diversity and distribution in Mediterranean ecosystems. We describe cyanobacterial diversity in Mediterranean semiarid soil crusts along an aridity gradient by using next-generation sequencing and bioinformatics analyses, and detect clear shifts along it in cyanobacterial dominance. Statistical analyses show that temperature and precipitation were major parameters determining cyanobacterial composition, suggesting the presence of differentiated climatic niches for distinct cyanobacteria. The responses to temperature of a set of cultivated, pedigreed strains representative of the field populations lend direct support to that contention, with psychrotolerant vs thermotolerant physiology being strain dependent, and consistent with their dominance along the natural gradient. Our results suggest a possible replacement, as global warming proceeds, of cool-adapted by warm-adapted nitrogen-fixing cyanobacteria (such as Scytonema) and a switch in the dominance of Microcoleus vaginatus by thermotolerant, novel phylotypes of bundle-forming cyanobacteria. These differential sensitivities of cyanobacteria to rising temperatures and decreasing precipitation, their ubiquity, and their low generation time point to their potential as bioindicators of global change.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: arid lands / Arid zones / Aridity / Biodiversity / Bioindicators / Bioinformatics / Biomonitoring / Climate / Climate change / Composition / Concretions / Crusts / Cyanobacteria / Cyanobacteria - genetics / Dominance / dry environmental conditions / Ecosystem / Ecosystems / global change / Global warming / heat tolerance / high-throughput nucleotide sequencing / Illumina sequencing / indicator / Indicator organisms / Indicator species / key topsoil microorganisms / Mediterranean Region / Microbiota / Microcoleus vaginatus / Niches / nitrogen-fixing cyanobacteria / phylotype / physiology / Precipitation / psychrotolerant cyanobacteria / Scytonema / semiarid soils / Soil / soil crusts / Soil Microbiology / Spain / Statistical analysis / Statistical methods / Temperature / thermotolerant cyanobacteria / Topsoil / trophic relationships