Differential Impacts of Water Table and Temperature on Bacterial Communities in Pore Water From a Subalpine Peatland, Central China

Abstract

The level of water table and temperature are two environmental variables shaping soil bacterial communities, particularly in peatland ecosystems. However, discerning the specific impact of these two factors on bacterial communities in natural ecosystems is challenging. To address this issue, we collected pore water samples across different months (August and November in 2017 and May 2018) with a gradient of water table changes and temperatures at the Dajiuhu peatland, Central China. The samples were analyzed with 16S rRNA high-throughput sequencing and Biolog EcoMicroplates. Bacterial communities varied in the relative abundances of dominant taxa and harbored exclusive indicator operational taxonomic units across the different months. Despite these differences, bacterial communities showed high similarities in carbon utilization, with preferences for esters (pyruvic acid methyl ester, Tween 40, Tween 80, and D-galactonic acid γ-lactone), amino acids (L-arginine and L-threonine), and amines (phenylethylamine and putrescine). However, rates of carbon utilization (as indicated by average well-color development) and metabolic diversity (McIntosh and Shannon index) in May and August were higher than those in November. Redundancy analysis revealed that the seasonal variations in bacterial communities were significantly impacted by the level of the water table, whereas the temperature had a fundamental role in bacterial carbon utilization rate. Co-occurrence analysis identified Sphingomonas, Mucilaginibacter, Novosphingobium, Lacunisphaera, Herminiimonas, and Bradyrhizobium as keystone species, which may involve in the utilization of organic compounds such as amino acids, phenols, and others. Our findings suggest that bacterial community functions were more stable than their compositions in the context of water table changes. These findings significantly expand our current understanding of the variations of bacterial community structures and metabolic functions in peatland ecosystems in the context of global warming and fluctuation of the water table.

Changes in the structure and function of rhizosphere soil microbial communities induced by Amaranthus palmeri invasion

“…palmeri rhizosphere soils and native rhizosphere soils, respectively ( Figures 6A , B ). This outcome corroborated previous findings that keystone taxa play critical roles in controlling soil microbial functional capacity ( Zhang et al, 2019 ; Shi et al, 2020 ; Tian et al, 2021 ). Besides, we further found that the keystone taxa in A .…”

“…We found that the keystone taxa best explained the functional genes with the explanation of 32.27 and 37.61% in A. palmeri rhizosphere soils and native rhizosphere soils, respectively (Figures 6A,B). This outcome corroborated previous findings that keystone taxa play critical roles in controlling soil microbial functional capacity (Zhang et al, 2019;Shi et al, 2020;Tian et al, 2021). Besides, we further found that the keystone taxa in A. palmeri rhizosphere soils were significantly positively correlated with the functional genes of soil microbial communities compared with native plants (Supplementary Figure S5A).…”

Denitrification Performance in Packed-Bed Reactors Using Novel Carbon-Sulfur-Based Composite Filters for Treatment of Synthetic Wastewater and Anaerobic Ammonia Oxidation Effluent

“…The autotrophs and heterotrophs were both abundant in S 1 –S 4 . The heterotrophs in S 1 –S 4 , including Ferruginibacter , Bacteroides , Trichococcus , Dokdonella , Herminiimonas , Sphingobium , and Cellulomonas , are associated with the degradation of organics or HD processes ( Chen et al, 2016 ; Han et al, 2020 ; Tian et al, 2021 ; Xin and Qiu, 2021 ; Zhang et al, 2021 ), and their abundances were both decreased or disappeared in S 5 –S 8 . The abundance of Rhodanobacter increased in R 1 and R 3 reactors, even though these bacteria are related to the degradation of carbohydrates ( Xin and Qiu, 2021 ).…”

Water table level controls methanogenic and methanotrophic communities and methane emissions in a Sphagnum -dominated peatland

“…Peat samples were collected in August 2017 from four Sphagnum -dominated sites: one each at Erhaoba and Niangniangfen, and two at Yangluchang, each with a different water table level. The water table level was determined with an Odyssey Logger (Dataflow Systems Limited, Christchurch) as previously described ( 43 ).…”