CHARACTERIZATION OF THE LEAF EPIDERMIS OF TWO SESLERIA SPECIES

Leaf epidermis has been used as character in taxonomy of Poaceae family since the 1930s. The purpose of present study was to determine leaf epidermal features helpful in distinguishing two species of Sesleria genus – Sesleria heufleriana Schur and Sesleria uliginosa Opiz.Both the abaxial and the adaxial epidermis have been examinated for each species.So both examined species have Festucoid type of epidermis, but differences of some epidermal features exist at the species level. This include variation in number and size of epidermal cells and distribution patterns of stomata

Erratum: Di Pietro, R., Kuzmanović, N., Lakušić, D., Viciani, D., Fortini, P. & Iamonico, D. (2021) Nomenclatural and taxonomic notes on some names of Sesleria sect. Argenteae (Poaceae) from Italy and the Balkans. Phytotaxa 494 (1): 89–102.

In our recent paper, we noticed a mistake concerning figure 2 (Di Pietro et al. 2021: 93). According to the caption, figure 2 should represent the sheet FI051890 (a lectotype of Sesleria nitida var. tenoreana f. visianii). In fact, in the place of the sheet FI051890, a figure containing two herbarium specimens deposited in PAD (PAD-HD00955 and PAD-HD00956) was erroneously published. These two PAD specimens were discussed in the paper (Di Pietro et al. 2021: 94) where it was highlighted that these could not be considered with certainty as original material for Sesleria nitida var. tenoreana f. visianii Pampanini (1917: 4). We here, correct the mistake and publish the image of lectotype of Sesleria nitida var. tenoreana f. visianii (FI051890, Fig. 1). Copyright © 2021 Magnolia Pres

Post-glacial determinants of regional species pools in alpine grasslands

[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.The authors thank Daniela Gaspar for support in GIS analyses. B.J.-A. thanks the Marie Curie Clarín-COFUND program of the Principality of Asturias-EU (ACB17-26), the regional grant IDI/2018/000151, and the Spanish Research Agency grant AEI/ 10.13039/501100011033. J.V.R.-D. was supported by the ACA17-02FP7 Marie Curie COFUND-Clarín grant. G.P.M. was funded by US National Science Foundation award 1853665. C.M. was funded by grant no. 19-28491 of the Czech Science Foundation.Peer reviewe