Kacper Foremnik, Ewa Błońska, Wojciech Piaszczyk, Jerzy Szwagrzyk, Remigiusz Pielech
Effects of natural disturbances on environmental conditions, understory plant diversity, and functional strategies in montane forests
Dendrobiology 2026, vol. 96: 111-126
https://doi.org/10.12657/denbio.096.009
Abstract:
Natural disturbances are major drivers of forest ecosystem dynamics, yet their combined effects on soil properties, understory vegetation, and plant functional strategies remain insufficiently understood, particularly in mountain forests. We investigated the impacts of large-scale natural disturbances on understory plant communities in the Tatra Mountains (southern Poland). Using a paired twin-plot study design, we compared vegetation composition, species diversity, ecological CSR strategies, and selected soil physicochemical properties between sites of long-term forest continuity and disturbed ones.
A total of 86 vegetation plots representing 43 paired disturbed-undisturbed sites were surveyed in 2020 and 2021. Species composition differed significantly between disturbed and undisturbed forests, indicating reorganization of understory communities after disturbances. Disturbed plots were characterized by a higher abundance of ferns, grasses, and expansive species, whereas undisturbed forests supported species typical of mature beech and spruce stands. Contrary to expectations, disturbance did not significantly affect soil carbon, nitrogen, C/N ratio, pH, or sum of exchangeable base cations. In contrast, disturbed sites exhibited significantly higher soil moisture and capillary water capacity. Species richness was slightly higher in disturbed forests, while species evenness was significantly lower, particularly at higher elevations, suggesting increased dominance of a limited number of species. Analyses of plant life strategies based on functional traits revealed a significantly lower contribution of ruderals in disturbed plots, whereas species representing competitive and stress-tolerant strategies did not differ between disturbance categories.
Our results indicate that the ecological consequences of bark beetle outbreaks and wind disturbances in the Tatra Mountains are driven primarily by changes in microclimatic and hydrological conditions rather than by nutrient enrichment. The observed patterns suggest that understory vegetation responses reflect relatively advanced successional stages, where competitive species dominate while ruderal species remain of minor importance.
Keywords: plant diversity, natural disturbances, forest dynamics, herbaceous plants, forest ecology, plants life strategies