Unravelling changes in the Pinus radiata root and soil microbiomes as a function of aridity

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 ..., , # 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\_enviro...,