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Aim: The aim of the paper is to describe species composition, ecology and syntaxonomy of unique mesophilous forests in Georgian Colchis in the context of the Euxinian forests. Location: SW Georgia, western part of the Caucasus Region, slopes of the Lesser Caucasus (80-990 m). Methods: Forest vegetation was sampled following the Braun-Blanquet approach and basic environmental characteristics were recorded for each relevé (n = 53). The dataset was clustered using modified TWINSPAN and diagnostic species for each cluster were defined by phi fidelity index. Links between the species composition of vegetation and environmental factors were analysed by detrended correspondence analysis. Numerical comparison of the distinguished clusters with previously published associations from northern Turkey was carried out (expanded dataset, n = 173). Results: Among the new relevés, we distinguished three vegetation types subsequently described as new associations: (i) Digitali schischkinii-Carpinetum betuli, chestnut-hornbeam forests of slightly dry sites, with low cover of evergreen shrubs, (ii) Rusco colchici-Castaneetum sativae, chestnut-hornbeam forests with a dense evergreen shrub layer, and (iii) Polysticho woronowii-Ulmetum glabrae, ravine forests with noble hardwood trees and ravine forest specialists. These associations were classified to the alliances of Euxinian forests, the first two to Castaneo-Carpinion and the third to Alnion barbatae. Major turnover in species composition within the dataset followed gradients of rockiness, slope inclination, altitude and mean annual temperature. The analysis of the expanded dataset revealed a decreasing occurrence of Mediterranean species and an increasing number of fern species along an easterly gradient. This change in species composition is likely to be driven by macroclimatic gradients. Conclusions: This paper presents the first numerical comparison of chestnut-hornbeam and ravine forests across central and eastern parts of the Euxinian Province. Our results have highlighted the uniqueness of Georgian Colchic forests, described as new associations, in the context of Euxinian forest vegetation. [ABSTRACT FROM AUTHOR]

The article focuses on the conversion of the names Galio-Carpinetum Oberdorfer 1957, Lithospermo-Carpinetum Oberdorfer 1957, and Stellario-Carpinetum Oberdorfer 1957. It mentions about mesophytic oak-hornbeam forests of the western and central parts of Central Europe, and thermophytic oak-hornbeam forests of southwestern Central Europe and the adjacent parts of France.

Aims: Western Podolia is one of several regions in the Eurasian forest-steppe zone where diverse steppe vegetation has been relatively well preserved. Our aims were to describe compositional turnover of steppe vegetation along different environmental gradients, to identify the patterns of species richness and evenness across complete compositional gradients and to outline biogeographical links of Western Podolian forest-steppe, with the emphasis on the generally rare mesic steppe types. Study area: Western Podolia and adjacent regions of Western Ukraine. Methods: Two independent datasets of vegetation plots and environmental variables were classified using modified TWINSPAN and ordinated using DCA and CCA. Diagnostic, constant and dominant species were identified. Ecological elements were quantified using Didukh indicator values. Biogeographical analysis was based on an extensive review of literature and NMDS of species frequency data sourced from studies covering a large part of Central and Eastern Europe. Results: The main gradients in species composition correspond to ecological gradients of 1) topographically controlled moisture and nutrient availability and 2) disturbance and human impact. The first gradient ranges from low-productive dry stands dominated by narrow-leaved tufted grasses, through dry-mesic stands co-dominated by broad-leaved grasses and herbs, to highproductive dry-mesic to mesic stands co-dominated by tall herbs and broad-leaved grasses. The second gradient tends towards communities altered by intensive human use. Species richness of steppe grasslands may be extremely high and has a unimodal relationship with estimated productivity. It peaks at mesic sites, in places with high evenness of species abundances. Conclusions: The remaining steppe fragments in Western Podolia are nowadays partly burnt, partly grazed, rarely mown and partly unmanaged. They harbour a number of rare light-demanding species and species reaching their distributional limits within the study area. Exceptional diversity of the grasslands may originate from Early Holocene or Pleistocene forest-steppe communities. [ABSTRACT FROM AUTHOR]