The study was aimed to investigate the effects of soil contamination and root herbivory on root surface area and stem anatomical properties that affect water conductivity in young common beech ( Fagus sylvatica L.) plants. Beech seedlings were planted for one growing season into pots filled with contaminated (Pb, Zn, and Cd) and uncontaminated soil in a free-air mesocosm experiment. In autumn, root herbivores summer chafer larvae ( Amphimallon solstitialis L.) were added into half of pots with contaminated and uncontaminated soil and left for 3 months. After destructive sampling, roots were measured for root surface area and stem sections were prepared and observed under the microscope. Ring width, vessel density, conductive area, potential conductivity, vessel grouping indexes, and vessel diameters were measured. In contaminated soil, root surface area, mean ring width, vessel radial diameter, and potential stem conductivity were significantly reduced compared to uncontaminated soil (by − 61.7, − 75.9, − 20.5, and − 78.8%, respectively), while vessel density, vessel grouping index, and mean group size of grouped cells were significantly increased (by + 38.7, + 15.8, and + 21.2%, respectively). Soil contamination induced stem anatomical changes similar to drought stress. Late exposure to root herbivory was insufficient to induce significant changes in root surface area or stem anatomy.