Microbial Communities in Biocrusts Are Recruited From the Neighboring Sand at Coastal Dunes Along the Baltic Sea

Abstract

Biological soil crusts occur worldwide as pioneer communities stabilizing the soil surface. In coastal primary sand dunes, vascular plants cannot sustain due to scarce nutrients and the low-water-holding capacity of the sand sediment. Thus, besides planted dune grass, biocrusts are the only vegetation there. Although biocrusts can reach high coverage rates in coastal sand dunes, studies about their biodiversity are rare. Here, we present a comprehensive overview of the biodiversity of microorganisms in such biocrusts and the neighboring sand from sampling sites along the Baltic Sea coast. The biodiversity of Bacteria, Cyanobacteria, Fungi, and other microbial Eukaryota were assessed using high-throughput sequencing (HTS) with a mixture of universal and group-specific primers. The results showed that the biocrusts recruit their microorganisms mainly from the neighboring sand rather than supporting a universal biocrust microbiome. Although in biocrusts the taxa richness was lower than in sand, five times more co-occurrences were identified using network analysis. This study showed that by comparing neighboring bare surface substrates with biocrusts holds the potential to better understand biocrust development. In addition, the target sequencing approach helps outline potential biotic interactions between different microorganisms groups and identify key players during biocrust development.

Microbial community composition of terrestrial habitats in East Antarctica with a focus on microphototrophs

“…Surprisingly, no cyanobacteria from order Nostocales were detected in the green sand sample (Skar35). In temperate regions, the diversity of cyanobacteria in sand is lower than in biocrusts, although heterocystous cyanobacteria are still present (Glaser et al, 2022). Besides, black sand sample (Pad3) contained several Nostocales genera.…”

Biocrusts: Overlooked hotspots of managed soils in mesic environments

“…Three main erosion‐reducing mechanisms in biocrusts have been described. First, the sticky filamentous structure of many pioneer microalgae and cyanobacteria can glue soil particles together (Glaser et al., 2018; Glaser, Albrecht, et al., 2022; Glaser, Van, et al., 2022). Second, biocrusts are able to store water and reduce the kinetic energy of raindrops relative to bare soil (Zhao et al., 2014), which can reduce overland runoff (Bu et al., 2015).…”

“…Biocrusts have been referred to as biogeochemical hotspots in mesic environments (Kuzyakov & Blagodatskaya, 2015). They host higher microbial biomass compared to surrounding bulk soil (Glaser, Albrecht, et al, 2022;Glaser, Van, et al, 2022;Kurth et al, 2021;Nevins et al, 2021), exhibit more nutrient turnover, and can consequently impact biogeochemical cycling (Glaser et al, 2018;Kurth et al, 2021). Recent work has found a carbon enrichment from microbial biomass and plantavailable nitrogen beneath biocrusts in agricultural soils (Nevins et al, 2020), and that biocrusts play a key role in the biogeochemical phosphorus cycle in forests (Baumann et al, 2017(Baumann et al, , 2019Kurth et al, 2021).…”

“…Kheirfam (2020) observed an increase in carbon sequestration when soils were inoculated with bacteria, cyanobacteria, or both, resulting in an extrapolated removal of 3.11-3.93 t ha -1 year -1 of CO 2 from the atmosphere. Several other studies have primarily been concerned with the composition of biocrust soil microbial communities (Glaser, Albrecht, et al, 2022;Glaser, Van, et al, 2022;Kurth et al, 2021;Nevins et al, 2021), and their changes with elevation and microclimates (You et al, 2021). However, further work F I G U R E 2 Summary of the potential beneficial effects of biocrusts in mesic environments (Illustration: Julia Dartsch) will be required to determine which specific organisms or community profiles contribute to these changes in biogeochemical cycling.…”

Bacterial community in biological soil crusts from a Brazilian semiarid region under desertification process

“…In addition, although BSC is mainly composed of cyanobacteria, eukaryotic algae, lichens, and bryophytes (Belnap and Lange, 2003), they can be highly biodiverse (Hernandez and Knudsen, 2012). It includes archaeal, bacterial, and fungal communities, which play essential biological processes, such as biomass degradation and nutrient cycling (Zhang et al, 2018a;Glaser et al, 2022).…”