Vegetation restoration types affect soil bacterial community composition and diversity in degraded lands in subtropical of China

Abstract

Significant improvement of soil quality and biodiversity has been reported following vegetation restoration on the degraded lands in subtropical of China. However, so far the response of soil bacterial communities and drivers of their composition to differing vegetation restoration types are not well understood. In this study, we investigated soil physicochemical properties and bacterial communities in degraded land subjected to differing vegetation restoration types after 12 years of long-term experiment. Restoration types included grassland, cropland, three differing plantation forests (orchard, coniferous forest, and coniferous forest with applied tillage), and control of degraded land. Bacterial community composition was examined using 16S rDNA sequencing. Result found that soil nutrient content includes soil organic carbon (SOC), total N (TN), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) was improved after 12-year restoration and the highest contents were found in cropland. However, soil pH was decreased after revegetation in the order degraded land > grassland > forestland > cropland, and the soil C/N ratio was significantly decreased in cropland. Revegetation restoration significantly increased operational taxonomic units (OTUs), ACE, and Chao1 indices by 13.67-22.81%, 16.34-25.11%, and 14.66-24.00%, with relative abundances of bacterial phyla varying between the different vegetation types. Soil physicochemical properties (e.g. pH, SOC, TN, AN, AP, and AK) showed significant correlations with the majority of the dominant phyla. When degraded land was restored to cropland, soil C/N ratio decreased which promoted the growth of Actinobacteria. Revegetation with grassland and forest increased soil nutrient content and decreased pH, resulting in shifts in bacterial phyla favoring Proteobacteria and Acidobacteria. Our observations show that restoration of degraded land will lead to differing bacterial community compositions depending on the vegetation type.

Response of Soil Microbial Communities and Functions to Long-Term Tea (Camellia sinensis L.) Planting in a Subtropical Region

“…Similar to the study reported by Nie et al [33] that proposed that copiotrophic microorganisms, including for example, Actinobacteria and Proteobacteria, generally increase under nutrient-rich conditions, while oligotrophic taxa, like Acidobacteria, show the opposite trend. Furthermore, RDA demonstrated that pH was the most important environmental variable driving the temporal and spatial distribution of bacteria in this paper, which is in line with previous studies [30,34]. However, we found a positive relationship between soil pH and Acidobacteria in this study, which contradicts most previous results [35], which may contribute to the inconsistent response of different Acidobacteria subgroups to changes in soil pH [36].…”

“…However, no significant correlations were detected for the Chao1, Shannon and Simpson indices of fungi, implying that soil bacterial richness and diversity responded more sensitively to environmental changes than fungi. Additionally, numerous studies have proved that soil pH is a prevailing determinant of soil bacterial diversity in many ecosystems [29,30]. In the present study, there was a strong positive correlation between soil pH and bacterial diversity index (Shannon and Simpson), but not with the fungal diversity, which further showed that bacteria were more sensitive to environmental changes than fungi in tea plantations.…”

Aggregate‐associated soil organic carbon fractions in subtropical soil undergoing vegetative restoration

“…For improving the ecosystem functions of the “red desert,” large scale vegetation restoration, carried out by the Chinese government, was implemented and has emerged as the region's top priority. Numerous studies have reported that this initiative is a feasible approach to increasing C sequestration in both vegetation and soils (Chu et al, 2018; Yu et al, 2021; Zheng et al, 2022), but few studies have focused on the quantitative effects vegetation type has on aggregate‐associated SOC fractions and optimization configurations. In our study area, a long‐term Forest Restoration Experiment Project (FREP), was designed and executed in 1991.…”