AbstractVascular plant species (VP) and bryophytes (B) constitute a significant portion of forest biodiversity and respond to both management intensity and natural disturbances within forests. In this study, we investigated the cross-taxa congruence between understorey VP and B at both diversity and composition levels across a wide range of sustainably managed forests in Slovenia. The taxonomic and functional characteristics of the selected plant groups were studied, with a particular emphasis on ground-dwelling species. We employed a trait-based approach to examine the functional characteristics. On average, the species richness of B in sustainably managed temperate forests increased with the corresponding number of VP. Furthermore, a moderate positive correlation in species composition between the studied groups of ground-dwelling organisms was also observed. The ground-dwelling VP and B were congruent in terms of trait-based composition, which was influenced by soil reaction and nutrients and light availability, while trait-based diversity was only slightly similar in response to moisture. A negative correlation between the composition of stress-tolerant VP and B hemeroby was found, indicating forest environments with a low level of disturbance. This is likely due to the sustainable management of Slovenian forests, where climate change and natural disturbances have intensified in recent years. A cross-taxon comparison of the two groups at four different levels, namely taxonomic-based diversity and composition and trait-based diversity and composition, revealed varying degrees of congruence. It is therefore important to monitor the status and temporal trends of both groups from different aspects to draw reliable conclusions.

AbstractHedera helix L. is an evergreen vine native to Europe. Nowadays, it is commonly recognized as an expansive species, posing danger to biodiversity of natural ecosystems. Obtaining the relationships between morphological variability, productive parameters of vegetative individuals, and variations in environmental factors (on the example of the Kórnik Arboretum) is important for understanding the successful adaptation and dispersion of H. helix. Thus, the issue of our studies was to discover the link between environmental factors and morphometric measurements of H. helix. We collected data on leaf length, leaf width, leaf petiole length, plant stem length, and the number of leaves per stem. We assessed values of ecological plasticity and correlation between the studied parameters. The results indicated the tolerance of ivy to wide variation in edaphic conditions. The limiting environmental factors for growth of the studied subpopulations were soil moisture and light intensity. We found large variability of leaf morphometric parameters and shoot length. Close correlation links were detected between leaf length/leaf width, leaf length/leaf petiole length, and leaf width/leaf petiole length. The length of the average leaf and the length of leaf petiole were the most variable parameters under different values of light intensity. Weak relationships were found between light intensity at the soil surface and plant stem length/the number of leaves per shoot. A high level of index of morphological integration of H. helix individuals and a close relationship between the quality index/subpopulation compositions were established in this study. A direct relationship between light intensity and specific leaf area values was established. The value of specific leaf area decreased linearly with increasing light intensity at the soil surface.