Diversity and Distribution Characteristics of Soil Microbes across Forest–Peatland Ecotones in the Permafrost Regions

Abstract

Permafrost peatlands are a huge carbon pool that is uniquely sensitive to global warming. However, despite the importance of peatlands in global carbon sequestration and biogeochemical cycles, few studies have characterized the distribution characteristics and drivers of soil microbial community structure in forest–peatland ecotones. Here, we investigated the vertical distribution patterns of soil microbial communities in three typical peatlands along an environmental gradient using Illumina high-throughput sequencing. Our findings indicated that bacterial richness and diversity decreased with increasing soil depth in coniferous swamp (LT) and thicket swamp (HT), whereas the opposite trend was observed in a tussock swamp (NT). Additionally, these parameters decreased at 0–20 and 20–40 cm and increased at 40–60 cm along the environmental gradient (LT to NT). Principal coordinate analysis (PCoA) indicated that the soil microbial community structure was more significantly affected by peatland type than soil depth. Actinomycetota, Proteobacteria, Firmicutes, Chloroflexota, Acidobacteriota, and Bacteroidota were the predominant bacterial phyla across all soil samples. Moreover, there were no significant differences in the functional pathways between the three peatlands at each depth, except for amino acid metabolism, membrane transport, cell motility, and signal transduction. Redundancy analysis (RDA) revealed that pH and soil water content were the primary environmental factors influencing the bacterial community structure. Therefore, this study is crucial to accurately forecast potential changes in peatland ecosystems and improve our understanding of the role of peat microbes as carbon pumps in the process of permafrost degradation.

Assessment of microbial communities from cold mine environments and subsequent enrichment, isolation and characterization of putative antimony- or copper-metabolizing microorganisms

“…For example, sites A and B exhibited a dominance of three distinct phyla: Actinomycetota, Pseudomonadota, and Bacillota. In contrast, site C showed a much more even distribution of phyla in the samples, including the high representation of Chloroflexota and Bacteroidota, which is consistent with results from earlier studies on frozen peatlands (Liu et al, 2022). At the genus level, differences between sites A and B were slightly more pronounced yet notably similar when compared to the genera observed in site C. In site A and B the dominant genera were Prauserella, Escherichia-Shigella and Alteribacillus.…”

Variation and Driving Mechanisms of Bark Thickness in Larix gmelinii under Surface Fire Regimes

“…Winters in the region can last up to 9 months with an average temperature below 10 • C, while summers typically last less than 1 month with an average temperature of approximately 22 • C. Over the past 40 years (1981-2020), the average annual temperature in the region was −4.3 • C and the average annual precipitation was 484.1 mm [27]. The soils in the region are predominantly dark-brown soil with relatively rich surface organic matter and high humus accumulation [28]. During the 2021-2022 field survey, we selected 26 stand sites in the region.…”

“…Over the past 40 years (1981-2020), the average annual temperature in the region was −4.3 °C and the average annual precipitation was 484.1 mm [27]. The soils in the region are predominantly darkbrown soil with relatively rich surface organic matter and high humus accumulation [28]. During the 2021-2022 field survey, we selected 26 stand sites in the region.…”