Clonal structure and reduced diversity of the invasive alien plant Erigeron annuus in Lithuania

Genetic Structure of Native Blue Honeysuckle Populations in the Western and Eastern Eurasian Ranges

Blue honeysuckle (Lonicera caerulea L.) is a promising berry crop producing edible early-ripening berries with a valuable chemical composition. We evaluated the genetic diversity of native L. caerulea populations from the western (Baltic states) and eastern (the Russian Far East and Japan) edges of the Eurasian range using inter-simple sequence repeat (ISSR) and chloroplast DNA (psbA-trnH and trnL-trnF) markers. The genetic relationships of populations and genotypes were analyzed using principal coordinate and cluster analyses (neighbor joining and Bayesian clustering). Sampling was carried out in two disjunct areas of this circumpolar species and the analyses showed clustering of individuals and populations according to geographic origin. The analysis of genetic structure based on ISSR markers showed that the studied populations of L. caerulea were highly differentiated. However, sequence analysis of two chloroplast DNA (cpDNA) regions revealed no phylogeographic structure among the populations. We also found that the eastern populations of blue honeysuckle had significantly greater genetic diversity parameters than the populations from the Baltic region. This finding correlates with the endangered status of blue honeysuckle in the Baltic states.

Effect of Urbanization on Vegetation in Riparian Area: Plant Communities in Artificial and Semi-Natural Habitats

Riparian areas are local hot spots of biodiversity that are vulnerable and easily degraded. Comparing plant communities in habitats with different degrees of urbanization may provide valuable information for the management and restoration of these vulnerable habitats. In this study, we explored the impact of urbanization on vegetation communities between artificial and semi-natural habitats within two rivers with different levels of development. We compared species richness, types of vegetation, and composition patterns of the plants in our study. In artificial habitats, the sites with relatively high levels of urbanization had the highest species richness, while in semi-natural habitats, the highest species richness was recorded in the less urbanized sites. Furthermore, every component of urbanization that contributed to the variation of species richness was examined in the current study. In artificial habitats, the proportion of impervious surface was the strongest predictor of the variation in species richness and was associated with the richness of alien, native, and riparian species. In semi-natural habitats, most of the richness of alien and native species were associated with the distance to the city center, and the number of riparian and ruderal species was significantly related to the proportion of impervious surface. Moreover, we found that a high level of urbanization was always associated with a large abundance of alien and ruderal species in both artificial and in semi-natural habitats. We recommend the methods of pair comparison of multiple rivers to analyze the impact of urbanization on plant species in riparian areas and have suggested various management actions for maintaining biodiversity and sustainability in riparian ecosystems.