Fine roots, endomycorrhizal colonization and soil moisture under throughfall exclusion in a sugar maple forest (Quebec, Canada, 2024–2025)

Data and R code supporting a throughfall exclusion study of fine root and endomycorrhizal responses to repeated growing-season soil water deficits in sugar maple (Acer saccharum Marsh.)-dominated forest (Kenauk Nature, southwestern Quebec, Canada).At each of two sites, about 75 % of throughfall was excluded from one 20 × 20 m plot during four growing seasons (2021–2024), and a second plot served as a control. Fine root mass density, soil bulk density and fungal colonization of fine roots were measured at 0–10, 10–20 and 20–30 cm in two subplots per plot, in July 2024 (final year of exclusion) and July 2025 (year after exclusion ended). The dataset also includes the soil moisture readings taken before fine root sampling, plot soil properties and subplot basal area.The two R scripts reproduce the mixed models, contrasts, figures and descriptive values of the associated article. See README.md for the variables and instructions.