Dataset Information

Characteristics of the Soil Microbial Communities in Different Slope Positions along an Inverted Stone Slope in a Degraded Karst Tiankeng.

ABSTRACT: The underground forests developed on inverted stone slopes in degraded karst tiankengs are important areas for biodiversity conservation, but the microbial community profiles have not been sufficiently characterized. Thus, we investigated the soil microbial communities at four sites (at the bottom of the slope (BS), in the middle of the slope (MS), in the upper part of the slope (US) and outside the tiankeng (OT)) in the Shenxiantang tiankeng. The dominant phyla in the inverted stone slope were Proteobacteria, Actinobacteria, and Acidobacteria, and the relative abundance were different in different slope positions. The Shannon-Wiener diversity index of the microbial community was significantly greater for the US site than for the MS or BS sites. The metabolism functional pathways (including C/N cycle) were more abundant at the BS site. Total nitrogen and pH were the dominant factors in determining the distribution of the microbial community along an inverted stone slope. These results suggest that topographic heterogeneity can influence the variations in the soil microbial structure, diversity, and function in degraded karst tiankengs and emphasized the ecological value of inverted stone slopes within karst tiankengs.

SUBMITTER: Jiang C

PROVIDER: S-EPMC8227116 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:The total dissolved organic matter (DOM) content of soil changes after vegetation transformation, but the diversity of the underlying chemical composition has not been explored in detail. Characterizing the molecular diversity of DOM and its fate enables a better understanding of the soil quality of monoculture forest plantations. This study characterized the chemodiversity of soil DOM, assessed the variation of the soil microbial community composition, and identified specific linkages between DOM molecules and microbial community composition in soil samples from a 100-year chronosequence of Chinese fir monoculture plantations. With increasing plantation age, soil total carbon and dissolved organic carbon first decreased and then increased, while soil nutrients, such as available potassium and phosphorus and total nitrogen, potassium, and phosphorus, increased significantly. Lignin/carboxylic-rich alicyclic molecule (CRAM)-like structures accounted for the largest proportion of DOM, while aliphatic/proteins and carbohydrates showed a decreasing trend along the chronosequence. DOM high in H/C (such as lipids and aliphatic/proteins) degraded preferentially, while low-H/C DOM (such as lignin/CRAM-like structures and tannins) showed recalcitrance during stand development. Soil bacterial richness and diversity increased significantly as stand age increased, while soil fungal diversity tended to increase during early stand development and then decrease. The soil microbial community had a complex connectivity and strong interaction with DOM during stand development. Most bacterial phyla, such as Acidobacteria, Chloroflexi, and Firmicutes, were very significantly and positively correlated with DOM molecules. However, Verrucomicrobia and almost all fungi, such as Basidiomycota and Ascomycota, were significantly negatively correlated with DOM molecules. Overall, the community of soil microorganisms interacted closely with the compositional variability of DOM in the monoculture plantations investigated, both by producing and consuming DOM. This suggests that DOM is not intrinsically recalcitrant but instead persists in soils as a result of simultaneous consumption, transformation, and formation by soil microorganisms with extended stand ages of Chinese fir plantations.

Dataset Information

Characteristics of the Soil Microbial Communities in Different Slope Positions along an Inverted Stone Slope in a Degraded Karst Tiankeng.

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