Bottom‐up versus top‐down control of tree regeneration in the Białowieża Primeval Forest, Poland

A seven-year study in the Białowieża Primeval Forest, one of Europe's most natural temperate forest ecosystems, revealed that tree regeneration is primarily controlled by different factors at distinct stages. Herbaceous vegetation cover was the dominant influence on seedling density, with an optimal cover of 38%. Soil fertility played a significant role in determining the density of saplings ≤ 50 cm, showing three times higher densities on eutrophic soils compared to oligotrophic ones. However, ungulate herbivory emerged as the key factor affecting tree recruitment into larger size classes (> 50 cm), with exclosures showing over three times more species recruiting and a more balanced species composition, while control plots exhibited dominance by the preferred forage species, Carpinus betulus. This suggests that ungulates can shape forest dynamics through selective browsing, coinciding with species tolerance to herbivory.

Kuijper, D. P. J., Cromsigt, J. P. G. M., Jędrzejewska, B., Miścicki, S., Churski, M., Jędrzejewski, W., & Kweczlich, I. (2010). Bottom‐up versus top‐down control of tree regeneration in the Białowieża Primeval Forest, Poland. Journal of Ecology, 98(4), 888–899. Portico. https://doi.org/10.1111/j.1365-2745.2010.01656.x