PhytOakmeter (www.phytoakmeter.de) is a field platform using the Quercus robur oak clone DF159 outplanted since 2010. This platform is used to monitor the impact of climate change and land use management on the "soil - plant - interactor" complex. Sites from PhytOakmeter are located either in forest or grassland habitats and represent a wide range of environmental contexts with specific stressors. All sites are equipped with loggers measuring air and soil temperature and soil humidity. Soil cores have been collected to analyze their chemical and physical characteristic.The FFOL plot in Fontain (France) started in 2013 with 13 oak trees outplanted over a 40m x 40m grassland plot. Soil and air temperature were measured since 2018, soil moisture was measured since 2019, and soil chemistry was assessed in the bulk soil and the root-affected zone of trees in 2015, 2018 and 2022. Soil porosity and texture were evaluated in 2023.