Bacterial Communities of Forest Soils along Different Elevations: Diversity, Structure, and Functional Composition with Potential Impacts on CO2 Emission

Abstract

Soil bacteria are important components of forest ecosystems, there compostion structure and functions are sensitive to environmental conditions along elevation gradients. Using 16S rRNA gene amplicon sequencing followed by FAPROTAX function prediction, we examined the diversity, composition, and functional potentials of soil bacterial communities at three sites at elevations of 1400 m, 1600 m, and 2200 m in a temperate forest. We showed that microbial taxonomic composition did not change with elevation (p = 0.311), though soil bacterial α-diversities did. Proteobacteria, Acidobacteria, Actinobacteria, and Verrucomicrobia were abundant phyla in almost all soil samples, while Nitrospirae, closely associated with soil nitrogen cycling, was the fourth most abundant phylum in soils at 2200 m. Chemoheterotrophy and aerobic chemoheterotrophy were the two most abundant functions performed in soils at 1400 m and 1600 m, while nitrification (25.59% on average) and aerobic nitrite oxidation (19.38% on average) were higher in soils at 2200 m. Soil CO2 effluxes decreased (p < 0.050) with increasing elevation, while they were positively correlated (r = 0.55, p = 0.035) with the abundances of bacterial functional groups associated with carbon degradation. Moreover, bacterial functional composition, rather than taxonomic composition, was significantly associated with soil CO2 effluxes, suggesting a decoupling of taxonomy and function, with the latter being a better predictor of ecosystem functions. Annual temperature, annual precipitation, and pH shaped (p < 0.050) both bacterial taxonomic and functional communities. By establishing linkages between bacterial taxonomic communities, abundances of bacterial functional groups, and soil CO2 fluxes, we provide novel insights into how soil bacterial communities could serve as potential proxies of ecosystem functions.

Energy storage in the forest ecosystem

“…The soil microorganisms also play an important role in plant litter degradation, thereby inducing changes in soil physical and chemical properties. 22,23 Specific exergy of the marine species reported by Semerciöz et al 14 was between 40 kJ/g when n = 1 and 1.48 Â 10 À3 when n = 5; in the present paper specific exergy of the sap consumed in step 1 was 1268 kJ/77 g = 66 kJ/g, in step n = 5 specific exergy become 4.68 Â 10 À2 . In the present paper, if the starting exergy specific exergy of the sap would have been 40 kJ/ g, specific exergy value attained in step n = 5 would be 2.83 Â 10 À2 , for example, 9% different than the number presented by Semerciöz et al 14 Exergy efficiency values reported by Semerciöz et al 14 were between 7.8 Â 10 À2 and 3.7 Â 10 À5 , while in the present paper, it is constant as 7.8 Â 10 À2 .…”

“…In addition to helping the plants to accumulate nitrogen, phosphorus, and sulfur in the soil, microorganisms accelerate nutrient cycling through organic matter decomposition and nitrogen‐fixing. The soil microorganisms also play an important role in plant litter degradation, thereby inducing changes in soil physical and chemical properties 22,23 …”

Soil bacterial succession with different land uses along a millennial chronosequence derived from the Yangtze River flood plain

“…Linking the variation of microbial communities to ecosystem functionality is a key challenge and the J o u r n a l P r e -p r o o f Journal Pre-proof ultimate goal in microbial ecology (Yan et al, 2020;Sun et al, 2022). While numerous studies have explored changes in bacterial communities, little research has focused on the resulting changes in ecological functions (Wang et al, 2019).…”

“…Research on these functional groups can provide valuable insights into the mechanisms underlying bacterial-mediated soil processes (Jiang et al, 2021). Recently, databases such as Functional Annotation of Prokaryotic Taxa (FAPROTAX), BugBase, and Tax4Fun, have been used to identify potential bacterial functions based on 16S rRNA gene sequencing (Li et al, 2019a;Jiang et al, 2021;Sun et al, 2022). Of these, FAPROTAX is particularly useful for monitoring soil ecology in agro-ecosystems, as it can annotate a series of functional bacteria, including those related to soil C, N nutrients cycling, predatory/exoparasitic and soil-borne pathogenic bacteria (Zhao et al, 2022).…”

Organic Inputs Positively Alter the Bacteriome of Post-Agricultural Soils

“…To increase forest cover and reduce the negative impacts of climate change on a global scale [1], both natural regeneration and silvicultural assumptions need to be implemented by growing forests on low-value land (including post-industrial land) and post-agricultural land exhausted by long-term use [2]. The long-term use of soils in agriculture (restricted crop rotation or monocultures) leads to their gradual degradation, especially in terms of biodiversity.…”