This dataset contains information on tree, site and soil properties from three oak woodland sites in southern England: Writtle Forest, Monks Wood, and Stratfield Brake. Data were collected in 2016 to investigate the relationship between Acute Oak Decline (AOD) symptoms and local environmental factors. The study included 10 symptomatic and 10 asymptomatic trees at each site. Tree characteristics include latitude and longitude coordinates, species-level classification (based on morphological measurements and genetic SNP analysis confirming identity as Quercus robur, Quercus petraea, or hybrids), tree dimensions (height, diameter at 1.35 m, crown dimensions), crown condition (density reduction), and rooting depth. Data on the surrounding site context were also collected, including depth to gleying, basal area of surrounding stands (measured at 0-20 m and 20-40 m), compound topographic index, and tree social status (e.g., dominant, codominant, suppressed). Soil characteristics were analysed to capture both physical and chemical properties. Physical properties included texture and bulk density, while chemical analyses measured organic matter content, pH, total carbon and nitrogen, mineral nitrogen (nitrate and ammonium), 'Olsen' extractable phosphorus, cation exchange capacity, and concentrations of exchangeable cations. The work was supported by the grant BB/N022831/1 ('PuRpOsE') with additional funding from the Woodland Trust, Bartlett's Tree Experts and The University of Reading. Full details about this dataset can be found at https://doi.org/10.5285/9947ccc9-7396-4821-b095-c374bd857305
