Barbora Šingliarová

Background and Aims: Several evolutionary drivers have been proposed to explain the exceptional species and genetic diversity of the Balkan flora, including the moderate impact of glaciations enabling long-term in situ persistence, ecological and topographic heterogeneity promoting vicariant differentiation, and polyploidy. Despite these shared drivers, plant lineages often show contrasting evolutionary histories, suggesting lineage-specific rather than broadly generalizable responses. The genus Erysimum, notable for its high endemism, karyological variation, recent and rapid speciation, and signatures of reticulate evolution, provides an excellent model for exploring this diversity of evolutionary trajectories and speciation drivers in the Balkans. Methods: Focusing on five Balkan endemics of the E. odoratum species complex sampled from 47 populations, we examined chromosomal and genome size variation and applied two complementary genomic approaches, target enrichment (Hyb-Seq) and RADseq, along with morphometric analyses. These datasets were used to circumscribe species, uncover intraspecific variation patterns and assess the extent and evolutionary consequences of interspecific gene flow and polyploidy. Key Results: Genetic and morphological evidence was largely congruent, clarifying species boundaries but also revealing cryptic diversity, leading to the recognition of eight entities. Most diversity was concentrated in the southern Dinarides, where we detected multiple cytotypes, an undescribed lineage, a polyphyletic species resulting from two independent autopolyploidization events, and allotetraploids arising in a contact zone. Geographical distance and biogeographical barriers across the mountainous Balkan landscape are likely to have shaped patterns of divergence and promoted speciation. Discrepancies between chromosome numbers and genome size indicate dynamic chromosomal evolution. Conclusions: Vicariant differentiation, auto- and allopolyploidy, genome size and chromosomal dynamics together account for the pronounced diversity of Erysimum in the Balkans, illustrating how speciation is driven within this biodiversity hotspot. Importantly, substantial evolutionary potential is retained within species, because the coexistence of multiple intraspecific genetic lineages and cytotypes can reinforce reproductive barriers and promote future diversification.

Novel invasive genotypes can arise through polyploidisation, hybridisation, or gene flow between populations of distinct origins or related species. Solida

Two perennial goldenrods, Solidago canadensis and S. gigantea (Asteraceae), are considered successful plant invaders with an exceptional ability to affect the biodiversity and environment of native ecosystems in Europe. However, their species-specific invasion impacts and associated ecological mechanisms shaping the species diversity of plant guilds and the soil conditions in grasslands remain poorly understood. Here, a spatial invasion-gradient approach with different invasion levels categorised by the percentage of goldenrod cover (heavily invaded > 50%, transitional invaded 20–50% and uninvaded control plots) was used to assess invasion impacts on species diversity of forbs, graminoids and bryophytes as well as on soil and vegetation properties in semi-natural grasslands of Slovakia (Central Europe). Multi-guild diversity assessment showed that graminoids were more tolerant than forbs of the competitive and stressful conditions in invaded plots. Invasion level reduced species richness of forbs in heavily invaded plots, likely owing to intensified competition and litter accumulation generated by dense Solidago stands. No invasion effect was found on graminoid and bryophyte species diversity metrics. Most variation in species diversity and ecological responses was addressed to the shared invasion impacts of both Solidago species, but several species-specific invasion effects on forb diversity indices and soil chemistry (soil reaction, nitrogen and potassium concentrations, C-to-N ratio) were also identified. The contrasting forb responses in Shannon and Simpson diversity indices corresponded to shifts in community evenness associated with species-specific effects of the invaders on soil nutrient cycling and productivity. Goldenrod invasions also altered community structure, primarily through shifts in abundance-dominance interactions rather than through substantial species replacement. Our results highlight the importance of recording invasion impacts across functional guilds and ecosystem components to better understand the mechanisms of plant invasion in semi-natural grasslands.

This paper presents new records and noteworthy data on the following taxa in Central Europe and adjacent regions: a stonewort Nitellopsis obtusa, lichens Absconditella lignicola, Lobaria pulmonaria, Multiclavula mucida, and Parmelia submontana, liverworts Mesoptychia heterocolpos and Sphaerocarpos europaeus, mosses Atrichum flavisetum, Campylopus pyriformis, Fabronia pusilla, Leptodon smithii, and Lewinskya acuminata, dicots Crataegus coccinea var. pringlei, Cuscuta approximata, Phedimus stoloniferus, and Tropaeolum majus, and monocot Sagittaria latifolia.

Author information: KMa, https://orcid.org/0000-0002-7658-0844; JK, https://orcid.org/0000-0002-9983-7630; RGA, https://orcid.org/0009-0000-0176-7252; JČ, https://orcid.org/0000-0002-2370-2051; AHE, https://orcid.org/0000-0002-7930-5696; SVG, https://orcid.org/0000-0002-7678-9648; AGG, https://orcid.org/0000-0002-4580-2061; AVH, https://orcid.org/0009-0009-4791-3919; IH, https://orcid.org/0000-0002-9905-381X; ZHH, https://orcid.org/0000-0001-8880-2144; IJ, https://orcid.org/0000-0003-2105-5310; TK, –; EK, https://orcid.org/0000-0001-9641-5750; FK, https://orcid.org/0000-0002-8793-7992; CL, https://orcid.org/0000-0002-2450-5455; TM, https://orcid.org/0000-0001-6485-0563; KMa, https://orcid.org/0000-0002-7658-0844; LYuM, https://orcid.org/0000-0001-9385-6462; LM, https://orcid.org/0000-0003-4478-5930; LAM, https://orcid.org/0000-0002-1283-3865; KMu, https://orcid.org/0000-0003-1585-6226; YMN, https://orcid.org/0000-0003-4749-0839; AAN, https://orcid.org/0000-0002-4380-7715; MN, https://orcid.org/0000-0002-1594-2418; AP, https://orcid.org/0000-0003-3620-6695; AVP, https://orcid.org/0009-0004-3522-5936; PP, https://orcid.org/0000-0001-8500-442X; BŠ, https://orcid.org/0000-0002-6487-6373; KS, https://orcid.org/0000-0002-1452-5428; MŠ, https://orcid.org/0000-0002-5919-890X; SŠ, https://orcid.org/0000-0003-4809-4379; GŠ, https://orcid.org/0000-0002-7439-2911; EZ, https://orcid.org/0000-0003-2992-2941; JZ‐L, https://orcid.org/0000-0002-8950-6643

Summary: Hybrid zones provide excellent opportunities to study evolutionary processes linked to interspecific gene flow, including introgression, genetic erosion, polyploid establishment, and speciation. The genus Cardamine (Brassicaceae) serves as an excellent model for polyploid evolution, including one of the few well‐documented neo‐allopolyploid species that have evolved in the last 300 yr. Using a combination of flow cytometric screening of nuclear DNA content, next‐generation restriction site‐associated DNA sequencing, and genomic in situ hybridization, we uncovered an unprecedented case of extensive interspecific hybridization in Cardamine , involving four parental species and their predominantly triploid offspring. We demonstrate the recurrent and polytopic origins of both autotriploids and allotriploids, the latter integrating different parental genomes. Our findings highlight Cardamine rivularis as a central player in this system, likely producing unreduced female gametes at a high rate, which drives the formation of diverse triploids. However, this species may also face the risk of genetic swamping and ecological displacement. The substantial genetic variation of the hybrids, their high frequency, partial fertility, and efficient clonal spread suggest significant evolutionary potential. Overall, we propose that these hybrid zones provide a rare and valuable natural laboratory for studying the emergence of neo‐allopolyploids and the mechanisms shaping polyploid evolution.

Background and aims: Invasive species represent a threat to the conservation of biological systems. Riparian ecosystems are vulnerable to plant invasions, as waterflow facilitates the dispersal of plant propagules, while invasive species may subsequently impact soil, including soil microbial communities. Downstream connectivity among disparate riverine segments is expected to cause spatial continuity of abiotic and biotic components of riparian ecosystems. Methods: We studied diversity of microbial communities in three headwater streams in Central Europe. Plant diversity, soil properties and soil microbiota were assessed on 20 sample plots per river. Soil microbial activity and community-level physiological profiling were used to study the soil microbial community. Results: While the α-diversity of plants and soil microbiota was similar among rivers, plant communities were substantially more differentiated than microbial communities. Richness in alien and invasive plants significantly differed among rivers, which was reflected in different spatial patterns of microbial activity and diversity. A high level of spatial continuity was observed in the Kysuca river with straightened riverbed and artificial surfaces in the adjacent areas. The cover of invasive plants affects the composition of microbial functional groups of riverbed soils. Conclusion: The expectation of spatial continuity of riverbed soil properties including those of soil microbiota caused by connectivity between different river segments was only partially fulfilled. Spatial continuity strongly depends on the environmental setting and stream characteristics of a particular river. The presence of invasive herbs affected the functional composition of soil microbiota but had no effect on microbial activity and diversity.

Aim: New areas are often simultaneously invaded by closely related alien species; however, between‐species differences in the course of their invasive spreading due to diverse ecological preferences have rarely been investigated. Here, we aim to study the species‐specific spatio‐temporal invasion patterns of Solidago canadensis and S. gigantea.Location: Slovakia—the Western Carpathian and adjacent Pannonian regions.Taxon: Invasive alien Solidago canadensis and S. gigantea.Methods: Our study was based on revised herbarium specimens, a recent field survey which included gathering abundance and habitat data, and environmental data from GIS layers. We characterised the environmental niche differentiation between S. canadensis and S. gigantea. Generalised additive models were then used to identify the key drivers of the species' occurrences and to assess their potential current and future distributions.Results: Both species began to spread in Slovakia in the 1850s; in the first 100 years, the number of S. gigantea sites increased exponentially, while that of S. canadensis remained low. Currently, S. canadensis is more widespread in the region. The species have similar habitat preferences. Their environmental niches overlap, but are not identical. The core distribution of S. canadensis is in foothills and valleys that experience lower annual mean temperatures, while that of S. gigantea is in lowlands with higher annual mean temperatures. A large part of their potential distribution areas seems to be already invaded. Possible future climate change could stimulate the spreading of S. canadensis into higher altitudes and S. gigantea farther into lowlands and Carpathian foothills.Main conclusions: The studied invasive Solidago species differed considerably in the early stages of invasion. Their environmental niches, current realised and potential distribution patterns are different. In the studied region, further spreading, with an increase in the number and size of populations, is likely unless effective measures are undertaken.