Data for: Fine-scale interventions can reinforce the forest character of the understory vegetation – The effects of different artificial gaps in an oak-dominated forest

Data of understory survey in the frame of Pilis Gap Experiment. The study was carried out in an oak-hornbeam forest in Hungary, in 2018-2023. Data were collected in every year, in four, artificially created gap types (large circular, large elongated, small circular, small elongated gaps) and in uncut control sites, in six replicates. List of understory species was established and percentage cover of each species was estimated in 2 m x 2 m quadrats. The cover of shrub layer and the height of the understory vegetation was also estimated. Species richness, sum of the species cover and cover of 5 functional groups (annual forbs, perennial forbs, graminoids, woody regeneration and cover of Rubus fruticosus agg. as an individual species group) were calculated. Relative direct and diffuse light were estimated by hemispherical photographs, and volumetric soil water content was also measured.