Taxonomic and functional biogeographies of soil bacterial communities across the Tibet plateau are better explained by abiotic conditions than distance and plant community composition

• Published in: Molecular ecology 2023-07, Vol.32 (13), p.3747-3762
• Main Authors: Liang, Qingqing, Mod, Heidi K., Luo, Shuaiwei, Ma, Beibei, Yang, Kena, Chen, Beibei, Qi, Wei, Zhao, Zhigang, Du, Guozhen, Guisan, Antoine, Ma, Xiaojun, Le Roux, Xavier
• Format: Article
• Language: English
• Subjects: 1500 km transect; Bacteria; Bacteria - genetics; Biochemistry, Molecular Biology; Biodiversity; Biogeography; Community composition; Composition; Dispersal; functional diversity; Functional groups; Life Sciences; Mathematical analysis; microbial biogeography; Moisture effects; nitrogen cycling; Organic matter; Organic soils; Plant communities; Plant populations; Plants; Soil - chemistry; Soil bacteria; Soil dynamics; Soil Microbiology; Soil microorganisms; Soil moisture; Soil pH; Soil temperature; Taxonomy; Tibet; Tibet plateau
• ISSN: 0962-1083; 1365-294X
• DOI: 10.1111/mec.16952

The processes governing soil bacteria biogeography are still not fully understood. It remains unknown how the importance of environmental filtering and dispersal differs between bacterial taxonomic and functional biogeography, and whether their importance is scale‐dependent. We sampled soils across the Tibet plateau, with distances among plots ranging from 20 m to 1550 km. Taxonomic composition of bacterial community was characterized by 16S amplicon sequencing and functional community composition by qPCR targeting 9 functional groups involved in N dynamics. Factors representing climate, soil and plant community were measured to assess different facets of environmental dissimilarity. Both bacterial taxonomic and functional dissimilarities were more related to abiotic dissimilarity than biotic (vegetation) dissimilarity or distance. Taxonomic dissimilarity was mostly explained by differences in soil pH and mean annual temperature (MAT), while functional dissimilarity was linked to differences in soil N and P availabilities and N:P ratio. Soil pH and MAT remained the main determinants of taxonomic dissimilarity across spatial scales. In contrast, the explanatory variables of N‐related functional dissimilarity varied across the scales, with soil moisture and organic matter having the highest role across short distances (~660 km). Our results demonstrate how biodiversity dimension (taxonomic versus functional aspects) and spatial scale influence the factors driving soil bacterial biogeography.