Soil Salinity and pH Drive Soil Bacterial Community Composition and Diversity Along a Lateritic Slope in the Avon River Critical Zone Observatory, Western Australia

Abstract

Soils are crucial in regulating ecosystem processes, such as nutrient cycling, and supporting plant growth. To a large extent, these functions are carried out by highly diverse and dynamic soil microbiomes that are in turn governed by numerous environmental factors including weathering profile and vegetation. In this study, we investigate geophysical and vegetation effects on the microbial communities of iron-rich lateritic soils in the highly weathered landscapes of Western Australia (WA). The study site was a lateritic hillslope in southwestern Australia, where gradual erosion of the duricrust has resulted in the exposure of the different weathering zones. High-throughput amplicon sequencing of the 16S rRNA gene was used to investigate soil bacterial community diversity, composition and functioning. We predicted that shifts in the microbial community would reflect variations in certain edaphic properties associated with the different layers of the lateritic profile and vegetation cover. Our results supported this hypothesis, with electrical conductivity, pH and clay content having the strongest correlation with beta diversity, and many of the differentially abundant taxa belonging to the phyla Actinobacteria and Proteobacteria. Soil water repellence, which is associated with Eucalyptus vegetation, also affected beta diversity. This enhanced understanding of the natural system could help to improve future crop management in WA since the physicochemical properties of the agricultural soils in this region are inherited from laterites via the weathering and pedogenesis processes.

Molecular Ecological Network Complexity Drives Stand Resilience of Soil Bacteria to Mining Disturbances among Typical Damaged Ecosystems in China

“…In this study, the method of network analysis revealed an appropriate way to discover how environmental changes affected microbial communities. Previous studies have shown that when the external environment changed, such as variations in soil properties, the diversity of microbial communities changed, which may be correlated with disturbances in soil characteristics [51][52][53]. Additionally, soil factors, such as pH, moisture content, total carbon content, and organic matter, have been reported to have a greater impact on the soil bacterial community structure and diversity in the ecological restoration of mining areas.…”

Impact of a Nature-Inspired Engineered Soil Structure on Microbial Diversity and Community Composition in the Bulk Soil and Rhizosphere of Tomato Grown Under Saline Irrigation Water

“…The highest soil salinity (EC e = 37 dS m −1 ) and lowest prokaryote diversity were found at bulk soils from the H plot irrigated with EC w of 9 dS m −1 . Most soil halophilic bacteria are expected to belong to Firmicutes, Proteobacteria (Das et al 2019), and Actinobacteria (O'Brien et al 2019). In this study, based on 16S rRNA sequencing, Proteobacteria was the most abundant phylum of bacteria, and its relative abundance increased by nearly 20% on average at the highest irrigation water salinity (EC w = 9 dS m −1 ) in comparison with the control with EC w of 0.8 dS m −1 .…”

“…Many field and laboratory experiments have shown the effects of salinity on decreasing soil microbial biomass, respiration, and enzymatic activity and diversity, especially in desert ecosystems (Wasserstrom et al 2017;Zhang et al 2019). Nonetheless, the extent to which the soil salinity drives microbial community changes is dependent on the nature of each study and its sample set (O'Brien et al 2019). Based on our experimental design and reviewed literature (Lozupone and Knight 2007), we Fig.…”

“…Salinity plays a critical role in soil environments, affecting ecological functions, including nutrient cycling and availability to plants (O'Brien et al 2019;Zhang et al 2019). When facing salinity stress, plants benefit from the activity of the microbial community colonizing the rhizosphere, namely due to increased nutrient uptake, microbial regulation of phytohormones, and suppression of soil-borne plant pathogens (Chaparro et al 2012;Kashyap et al 2020;Martínez-Viveros et al 2010;Rojas-Solis et al 2020;Schloter et al 2018).…”

Molecular ecological network complexity drives stand resilience of soil bacteria to mining disturbances among typical damaged ecosystems in China

“…In this study, the method of network analysis revealed an appropriate way to discover how environmental changes affected microbial communities. Previous studies have shown that when the external environment changed, such as variations in soil properties, the diversity of microbial communities changed, which may be correlated with disturbances in soil characteristics [46][47][48]. Additionally, soil factors, such as pH, moisture content, total carbon content, and organic matter, reportedly have had a greater impact on soil bacterial community structure and diversity in the ecological restoration of mining areas.…”