Organic Carbon Mineralization and Bacterial Community of Active Layer Soils Response to Short-Term Warming in the Great Hing’an Mountains of Northeast China

Abstract

As a buffer layer for the energy and water exchange between atmosphere and permafrost, the active layer is sensitive to climate warming. Changes in the thermal state in active layer can alter soil organic carbon (SOC) dynamics. It is critical to identify the response of soil microbial communities to warming to better predict the regional carbon cycle under the background of global warming. Here, the active layer soils collected from a wetland-forest ecotone in the continuous permafrost region of Northeastern China were incubated at 5 and 15°C for 45 days. High-throughput sequencing of the 16S rRNA gene was used to examine the response of bacterial community structure to experimental warming. A total of 4148 OTUs were identified, which followed the order 15°C > 5°C > pre-incubated. Incubation temperature, soil layer and their interaction have significant effects on bacterial alpha diversity (Chao index). Bacterial communities under different temperature were clearly distinguished. Chloroflexi, Actinobacteria, Proteobacteria, and Acidobacteria accounted for more than 80% of the community abundance at the phylum level. Warming decreased the relative abundance of Chloroflexi and Acidobacteria, while Actinobacteria and Proteobacteria exhibited increasing trend. At family level, the abundance of norank_o__norank_c__AD3 and Ktedonobacteraceae decreased significantly with the increase of temperature, while Micrococcaccac increased. In addition, the amount of SOC mineralization were positively correlated with the relative abundances of most bacterial phyla and SOC content. SOC content was positively correlated with the relative abundance of most bacterial phyla. Results indicate that the SOC content was the primary explanatory variable and driver of microbial regulation for SOC mineralization. Our results provide a new perspective for understanding the microbial mechanisms that accelerates SOC decomposition under warming conditions in the forest-wetland ecotone of permafrost region.

Soil bacterial community is influenced by long‐term integrated soil fertility management practices in a Ferralsol in Western Kenya

“…These comprised of Proteobacteria, Actinobacteria, Firmicutes and Acidobacteria . This observation coincides with the previous findings reported in Kenya (Karanja et al, 2020) and elsewhere (Dong et al, 2021; Wang, Wang, et al, 2018). These bacterial communities are ubiquitous in nature.…”

“…In contrast, long‐term application of nitrogen‐based inorganic fertilisers has been associated with soil acidification, reduced SOC and depressed abundance and diversity of particular microbial strains (Körschens, 2006; Leroy et al, 2008; Tian & Niu, 2015). Thus, different studies have reported contrasting and inconsistent bacterial responses to various soil chemical parameters; some documenting enrichment of bacterial dynamics with favourable soil pH (Rousk et al, 2010; Wang et al, 2019), SOC (Dong et al, 2021), macronutrients and secondary nutrients (Wang, Jiang, et al, 2018; Wang, Wang, et al, 2018); others recording negative bacterial responses to specific nutrients (Hu et al, 2021; Zheng et al, 2017), or no change (Wang, Jiang, et al, 2018; Wang, Wang, et al, 2018; Wang et al, 2019).…”

“…Soil bacteria are involved in carbon and nutrient cycling, biocontrol, aggregate formation and stabilisation (Gougoulias et al, 2014; Palaniyandi et al, 2013; Sahu et al, 2017), but their community structure is primarily limited by nutrient availability, soil organic carbon (SOC) and pH (Rousk et al, 2010; Wang et al, 2019; Wei et al, 2017). Favourable soil pH (Rousk et al, 2010; Wang et al, 2019), increased SOC (Dong et al, 2021), availability of macronutrients and secondary nutrients (Wang, Jiang, et al, 2018; Wang, Wang, et al, 2018) are known to improve soil microbial dynamics. Fluctuations in soil pH can either promote development of bacterial structure adapted to acidic environments, like Acidobacteria (Sait et al, 2006; Ward et al, 2009), or depress the abundance and diversity of nonacid tolerant bacterial strains like Proteobacteria (Lauber et al, 2009; Rousk et al, 2010).…”

Response of Carbon Emissions and the Bacterial Community to Freeze–Thaw Cycles in a Permafrost-Affected Forest–Wetland Ecotone in Northeast China

“…This result indicated that FTCs affect carbon emissions via soil substrates and the bacterial community. Dong et al [ 95 ] found there were significantly positive relationships between CO 2 emissions and most bacterial phyla abundances and diversity. Microbial community structure in the permafrost region is also a good predictor of CO 2 emissions [ 96 ].…”

Plant-Microbe Interaction in Sustainable Agriculture: The Factors That May Influence the Efficacy of PGPM Application

“…It is necessary to differentiate between species or microbial abundance (total number of individuals of a species or total size of the microbial biomass, respectively), species richness (total number of species), species uniformity (relative number of species), species identity or composition community (types of species/taxa present), and the diversity of species or ecosystems, which represent the number and frequency of species. For example, changes in microbial abundance have been identified as more important for soil carbon mineralization than differences in the composition of the microbial community [243].…”