DOI: 10.5061/dryad.6q573n688
title: Unravelling changes in the Pinus radiata root and soil microbiomes as a function of aridity

description: Rising aridity is becoming a major consequence of climate change,
 impacting terrestrial ecosystems worldwide. Forest biomes are especially
 at risk due to their long lifespan and immobility, making them vulnerable
 to shifting environmental conditions. Over time, microbiomes have evolved
 alongside plants, fostering mutual benefits. However, rapid environmental
 changes and plant domestication may disrupt the ability of plants to
 recruit beneficial microbial partners that enhance stress tolerance. This
 study examines how aridity influences the symbiotic relationship between
 tree roots and microbes, focusing on the widely planted Pinus radiata. By
 analyzing samples across a broad geographic range and varying
 environmental conditions, we explore how aridity, soil properties, and
 climate factors shape microbial communities in P. radiata roots and
 surrounding soils. Our findings show that while aridity plays a major role
 in shaping microbial community assembly, factors like soil pH and organic
 carbon strongly influence bacterial diversity. Certain bacterial and
 fungal taxa were found to be conditionally associated with aridity,
 emphasising their potential role in Pinus radiata resilience
 under increasing environmental stress. As mesic ecosystems shift toward
 arid conditions due to climate change, the presence of these
 aridity-associated taxa varies in bulk soils expected to become drier.
 This raises concerns that these beneficial microbes may need to be
 recruited through alternative mechanisms to support tree adaptation.
description: # Unravelling changes in the Pinus radiata root and soil microbiomes as a
 function of aridity Dataset DOI:
 [10.5061/dryad.6q573n688](10.5061/dryad.6q573n688) ## Description of the
 data and file structure The chemical and environmental file contains the
 GPS location of each sample site and the climate data were extracted at
 each sample location from the WorldClim 2.1 database. Aridity values were
 then determined from the Global Aridity Index (AI) and Potential
 Evapotranspiration Database. Soil from each location was characterised in
 physicochemical properties using Fourier-transformed, diffuse reflectance,
 mid-infrared spectroscopy (FT-IR). Predictions were made against the
 National Soil Survey Center–Kellogg Soil Survey Laboratory. The phyloseq
 files were generated through 16S and ITS Illumina Miseq amplicon
 sequencing, analysed through dada2 standard pipelines and turned into
 sequence count and taxonomy tables. ### Files and variables #### File:
 Supplementary\_table\_chem\_environ\_-\_updated\_March2025.txt
 **Description:** Chemical and environmental data ##### Variables *
 SampleID: An individual sample ID - each one represents a single sampling
 tree * Latitude_Longitude: GP coordinates for location of sampling * Av_P:
 Available phosphorus (mg/kg) * Total_S: Total sulfur (w%) * Organic_C:
 Organic carbon (wt%) * pH: pH * Sand: Sand content (wt%) * Silt: Silt
 content (wt%) * Clay: Clay content (wt%) * Exch_Ca: Exchangeable calcium
 (cmol(+)/kg) * Exch_Mg: Exchangeable magnesium (cmol(+)/kg) * Exch_Na:
 Exchangeable sodium (cmol(+)/kg) * C.N_ratio: Organic to nitrogen ratio *
 AridityIndex: Aridity Index * MeanTemp: BIO1-WorldClim bioclimatic
 variable 1, Mean annual temperature (°C) * TempSeason: BIO4 - WorldClim
 bioclimatic variable 4, temperature seasonality (standard deviation x100)
 (°C) * PrecipSeason: BIO15 - WorldClim bioclimatic variable 15,
 percipitation seasonality (coefficient of variation) (mm) ##### File:
 phyloseq\_data\_16S.zip **Description:** 16S data - contains a count table
 (sequence abundance data separated into each ASV). It also contains a
 taxonomy table where each ASV has been classified to its highest
 phylogenetic classification. ##### File: phyloseq\_data\_ITS.zip
 **Description:** ITS data - contains a count table (sequence abundance
 data separated into each ASV). It also contains a taxonomy table where
 each ASV has been classified to its highest phylogenetic classification.
 ### Access information Other publicly accessible locations of the data: *
 NCBI sequence read archive (SRA) under the BioProject accession
 PRJNA1217937