Temporal shifts in ground vegetation characteristics on newly constructed forest road verges

Forest road verges are common secondary habitats in managed forest landscapes, yet their vegetation development remains insufficiently documented. We investigated successional changes in ground vegetation on newly built forest road verges over an eight-year period using six repeated surveys, analysing taxonomic diversity, ecological indicator values and their Rao’s quadratic entropy, as well as functional trait composition based on Grime’s CSR strategies and Raunkiær’s life-forms. Our results showed a continuous increase in taxonomic richness throughout the study period, while niche differentiation increased mainly after the first year following road construction and remained relatively stable thereafter. Among the ecological preference indicators examined, nutrient availability consistently showed the highest niche differentiation, whereas light and moisture showed comparatively lower variation. Functional composition shifted from ruderal-dominated communities toward an increasing representation of stress-tolerant and competitive species. The obtained results of mixed-effects models revealed high spatial variation among road sections, indicating that early secondary succession on forest road verges is shaped by both successional processes and local environmental conditions.