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

This dataset contains Cynipid gall abundance from an oak provenance trial at Petite Charnie in France. 2400 trees were sampled from 20 provenances of Quercus petraea and Quercus robur in 2008 and 2009. Cynipids have two gall generations each year so trees were sampled in spring (sexual generation) and autumn (asexual generation). 10 twigs were surveyed for galls on all parts of the terminal shoot (buds, leaves, stem, catkins) from each tree in spring and autumn. Counts were made for each species and generation. Full details about this dataset can be found at https://doi.org/10.5285/1c99f7ad-6ae3-4891-801c-e3babdb61887

The dataset contains information from 234 trees at six sites across the UK collected in 2018. The tree species studied were Acer pseudoplatanus (sycamore), Castanea sativa (sweet chestnut), Fagus sylvatica (beech), Fraxinus excelsior (common ash), Quercus cerris (Turkey oak), Q. petraea (sessile oak), Q. robur (pedunculate oak), Q. rubra (red oak) and Tilia x europaea (common lime). The presence of all lichens and bryophyte species on the trunk to a height of 1.75m were recorded in addition to the presence of the lichens on branches and twigs where these were accessible. The bark characteristics recorded were bark pH, ridge and furrow width, furrow depth, hardness, water holding capacity and the bark patterning. The soil variables studied were: nitrogen mineralization and decomposition rate, total soil carbon and nitrogen, loss on ignition, soil pH and soil temperature. Fourier-transform infrared (FTIR) spectroscopy data from the soil samples is also presented along with data on site location and the habitat characteristics surrounding the sampled trees. Full details about this dataset can be found at https://doi.org/10.5285/f539567f-a8cd-482e-89b8-64a951b52d93