Abundance and biogeography of methanogenic and methanotrophic microorganisms across European streams

Abstract

Aim Although running waters are getting recognized as important methane sources, large‐scale geographical patterns of microorganisms controlling the net methane balance of streams are still unknown. Here we aim at describing community compositions of methanogenic and methanotrophic microorganisms at large spatial scales and at linking their abundances to potential sediment methane production (PMP) and oxidation rates (PMO). Location The study spans across 16 European streams from northern Spain to northern Sweden and from western Ireland to western Bulgaria. Taxon Methanogenic archaea and methane‐oxidizing microorganisms. Methods To provide a geographical overview of both groups in a single approach, microbial communities and abundances were investigated via 16S rRNA gene sequencing, extracting relevant OTUs based on literature; both groups were quantified via quantitative PCR targeting mcrA and pmoA genes and studied in relation to environmental parameters, sediment PMP and PMO, and land use. Results Diversity of methanogenic archaea was higher in warmer streams and of methanotrophic communities in southern sampling sites and in larger streams. Anthropogenically altered, warm and oxygen‐poor streams were dominated by the highly efficient methanogenic families Methanospirillaceae, Methanosarcinaceae and Methanobacteriaceae, but did not harbour any specific methanotrophic organisms. Contrastingly, sediment communities in colder, oxygen‐rich waters with little anthropogenic impact were characterized by methanogenic Methanosaetaceae, Methanocellaceae and Methanoflorentaceae and methanotrophic Methylococcaceae and Cd. Methanoperedens. Representatives of the methanotrophic Crenotrichaceae and Methylococcaceae as well as the methanogenic Methanoregulaceae were characteristic for environments with larger catchment area and higher discharge. PMP increased with increasing abundance of methanogenic archaea, while PMO rates did not show correlations with abundances of methane‐oxidizing bacteria. Main conclusions Methanogenic and methanotrophic communities grouping into three habitat types suggest that future climate‐ and land use changes may influence the prevailing microbes involved in the large‐scale stream‐related methane cycle, favouring the growth of highly efficient hydrogenotrophic methane producers. Based on these results, we expect global change effect on PMP rates to especially impact rivers adjacent to anthropogenically disturbed land uses.

Effects of Fir-Wood Biochar on Ch4 Oxidation Rates and Methanotrophs in Landfill Cover Soils Packed at Three Different Proctor Compaction Levels

“…However, this did not reflect in increased CH 4 oxidation rates. Very clearly, abundance and CH oxidation rates were unrelated over the entire sample set of loose and compacted soils, with and without biochar, as reported in other studies from natural environments (Hunt et al, 2013;Nagler et al, 2021). Methanotrophic abundance also showed no relation to compaction, in either of the soils since the increase in Methylocystis upon biochar amendment in coarse Soil C was neither related to oxidation rates nor compaction and hence volumetric water content and air-filled porosity.…”

Use of trait concepts and terminology in freshwater ecology: Historic, current, and future perspectives

“…Clear definition and critical evaluation of approaches adopting supra‐individual scales of trait measurement will help to clarify the scope of application and advantages in freshwater science. Besides phenotypes, the use of molecular features across the continuum from genes to proteins could foster the application of a trait‐based approach to microorganismal studies (Nagler et al., 2021; Powell et al., 2015; Trivedi et al., 2016) and increase the capabilities of the trait‐based approaches in macroorganisms (Martini et al., 2021). Genotypic characteristics such as functional gene markers of enzymes (Nagler et al., 2021; Trivedi et al., 2016) and genome characteristics (Barberán et al., 2012) have proved useful descriptors of organism performance, functional roles and environmental responses.…”

“…Besides phenotypes, the use of molecular features across the continuum from genes to proteins could foster the application of a trait‐based approach to microorganismal studies (Nagler et al., 2021; Powell et al., 2015; Trivedi et al., 2016) and increase the capabilities of the trait‐based approaches in macroorganisms (Martini et al., 2021). Genotypic characteristics such as functional gene markers of enzymes (Nagler et al., 2021; Trivedi et al., 2016) and genome characteristics (Barberán et al., 2012) have proved useful descriptors of organism performance, functional roles and environmental responses. Non‐inherited cultural traits are also recognised by our definition, allowing their integration into the functional trait approach and extending its advantages to the study of organisms with complex hierarchies and cultural systems, such as freshwater cetaceans, water birds, or elephants (Cantor et al., 2015; Hill et al., 2008).…”

Substantial warming of Central European mountain rivers under climate change

“…In mountain areas, air temperatures increased faster than the global average (Pepin et al 2015 ; Gobiet et al 2014 ) and led to accelerated global glacier mass loss (Zemp et al 2015 ; Hugonnet et al 2021 ) and faster warming of high-altitude streams (Niedrist and Füreder 2021 ) in the twenty-first century. Water temperature is generally one of the crucial conditions that regulates biological and geochemical structures and processes in freshwaters (Woodward et al 2010 ; Bravo et al 2018 ; Nagler et al 2021 ; Bernabé et al 2018 ). In mountain streams, this factor has demonstrated effects on the distribution and range of native freshwater species (Giersch et al 2015 ), on the performance and growth of invertebrates (Füreder and Niedrist 2020 ; Niedrist et al 2018a ), on the formation of thermal niches for non-native species (Khamis et al 2015 ; Rahel and Olden 2008 ), on the survival and fitness of cold-water fish (Young et al 2018 ; Al-Chokhachy et al 2013 ), or on stream metabolism (Acuña et al 2008 ; Ferreira and Canhoto 2015 ).…”