Aim Alpine habitats support unique biodiversity confined to high‐elevation areas in the current interglacial. Plant diversity in these habitats may respond to area, environment, connectivity and isolation, yet these factors have been rarely evaluated in concert. Here we investigate major determinants of regional species pools in alpine grasslands, and the responses of their constituent species groups. Location European mountains below 50° N. Time period Between 1928 and 2019. Major taxa studied Vascular plants. Methods We compiled species pools from alpine grasslands in 23 regions, including 794 alpine species and 2,094 non‐alpines. We used species–area relationships to test the influence of the extent of alpine areas on regional richness, and mixed‐effects models to compare the effects of 12 spatial and environmental predictors. Variation in species composition was addressed by generalized dissimilarity models and by a coefficient of dispersal direction to assess historical links among regions. Results Pool sizes were partially explained by current alpine areas, but the other predictors largely contributed to regional differences. The number of alpine species was influenced by area, calcareous bedrock, topographic heterogeneity and regional isolation, while non‐alpines responded better to connectivity and climate. Regional dissimilarity of alpine species was explained by isolation and precipitation, but non‐alpines only responded to isolation. Past dispersal routes were correlated with latitude, with alpine species showing stronger connections among regions. Main conclusions Besides area effects, edaphic, topographic and spatio‐temporal determinants are important to understand the organization of regional species pools in alpine habitats. The number of alpine species is especially linked to refugia and isolation, but their composition is explained by past dispersal and post‐glacial environmental filtering, while non‐alpines are generally influenced by regional floras. New research on the dynamics of alpine biodiversity should contextualize the determinants of regional species pools and the responses of species with different ecological profiles.

Polyploidization has played an important role in the diversification of the genus Sesleria (Poaceae), which comprises c. 48 species and subspecies mostly distributed in Europe. The genus' centre of diversity clearly is the Balkan Peninsula, harbouring about 80% of the species, half of which are endemic to this area. We employed chromosome counts, measurements of absolute genome size and determination of relative DNA-content for 460 populations belonging to 43 species of Sesleria. Our main aim was to provide essential baseline data for future molecular genetic reconstructions of the genus' evolutionary history. Relative genome size allowed for a mostly clear separation of four ploidy levels. The most frequent and widespread cytotypes are tetraploids followed by octoploids, while di-and dodecaploids were only found in a few species. We present first chromosome numbers for the tetraploid species S. doerfleri, S. phleoides, S. skipetarum and S. tuzsonii as well as for diploid S. ovata. Based on relative and partly also on absolute genome size measurements, ploidy level was determined in tetraploid S. rhodopaea and S. voronovii for the first time, and new cytotypes were identified in S. interrupta, S. kalnikensis and S. wettsteinii (tetraploids), S. caerulea, S. klasterskyi, S. latifolia, S. tenerrima, S. ujhelyii and S. vaginalis (octoploids), and S. albanica and S. vaginalis (dodecaploids). While most Sesleria species are ploidy-uniform, several comprise two or even, in the case of S. vaginalis, three ploidy levels. Genome downsizing after polyploidization was confirmed by significant negative correlation between ploidy level and monoploid genome size. Finally, we found a significant increase in monoploid relative genome size towards the margin of the genus' distribution area, which may be triggered by increased activity of transposable element in populations exposed to environmental or genomic stress.

The inventory of woody vegetation is of great importance for good forest management. Advancements of remote sensing techniques have provided excellent tools for such purposes, reducing the required amount of time and labor, yet with high accuracy and the information richness. Sentinel-2 is one of the relatively new satellite missions, whose 13 spectral bands and short revisit time proved to be very useful when it comes to forest monitoring. In this study, the novel spatio-temporal classification framework for mapping woody vegetation from Sentinel-2 multitemporal data has been proposed. The used framework is based on the probability random forest classification, where temporal information is explicitly defined in the model. Because of this, several predictions are made for each pixel of the study area, which allow for specific spatio-temporal aggregation to be performed. The proposed methodology has been successfully applied for mapping eight potential forest and shrubby vegetation types over the study area of Serbia. Several spatio-temporal aggregation approaches have been tested, divided into two main groups: pixel-based and neighborhood-based. The validation metrics show that determining the most common vegetation type classes in the neighborhood of 5 × 5 pixels provides the best results. The overall accuracy and kappa coefficient obtained from five-fold cross validation of the results are 82.97% and 0.75, respectively. The corresponding producer’s accuracies range from 36.74% to 97.99% and user’s accuracies range from 46.31% to 98.43%. The proposed methodology proved to be applicable for mapping woody vegetation in Serbia and shows a potential to be implemented in other areas as well. Further testing is necessary to confirm such assumptions.

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Reconstruction of relationships among populations of the morphologically polymorphic and taxonomically intricate Sesleria rigida sensu Fl. Eur. based on Amplified Fragment Length Polymorphisms (AFLPs) revealed four clearly differentiated genetic groups that did only partly follow recent taxonomic concepts, but were strictly allopatric. While some of the previously described taxa constitute distinct genetic entities, others have no taxonomic value. Synthesizing our AFLP data with ploidy‐level information obtained from all genetically investigated individuals as well as with chromosome counts revealed that tetraploid individuals prevail, while octoploids occur only within S. filifolia. Lack of AFLP divergence between tetra‐ and octoploids suggests an autopolyploid origin of the latter. The genetic differentiation pattern was reflected by morphological differentiation, allowing for a taxonomic revision of the constituents of S. rigida sensu Fl. Eur. resulting in recognition of the four species S. achtarovii, S. filifolia, S. rigida, and S. serbica.