Search

Questions: What are the main vegetation types of forest and shrubland vegetation in central and eastern Euxine Turkey and SW Georgia? What are the main environmental factors affecting their diversity? What is their syntaxonomic position? Can we integrate them into the European vegetation classification system? Location: Central and eastern Euxine Turkey and SW Georgia. Methods: We collected 3104 vegetation plots of forest and shrubland vegetation in the study region and performed Two‐Way Indicator Species Analysis (TWINSPAN) classification. We described vegetation types based on the classification results, expert knowledge and information from literature sources. We defined diagnostic species and prepared distribution maps for each vegetation type. To determine the most significant environmental variables on floristic differentiation, we used canonical correspondence analysis. Detrended correspondence analysis with passive projection of most significant environmental variables was run to interpret the environmental variation of vegetation types. Results: The studied vegetation was divided into 29 vegetation types related to seven main vegetation groups: relict Mediterranean forests and shrubland (mainly along the coastline, beside some inland localities), lowland to submontane forests, central Euxine mountain forests, eastern Euxine (Colchic) mountain forests, subeuxine forests, azonal riparian forests and subalpine and alpine shrubland. Elevation is the most important factor causing the differentiation in vegetation. It is followed by longitude and latitude. Among climatic variables, temperature seasonality, annual precipitation and precipitation of the wettest quarter are the most significant factors for vegetation differentiation. These factors correlate with the reduction of maritime climate and geomorphological features. Conclusions: Vegetation types mostly correspond to the syntaxa accepted in the EuroVegChecklist. However, some of them do not appear in the EuroVegChecklist since they appear only beyond Europe. We described three syntaxa as new: Abietion equi‐trojani, Querco cerridis‐Carpinion orientalis and Piceo orientalis‐Fagenion orientalis. The study revealed high vegetation diversity of the region that should be taken into consideration in ecosystem management and used as a reference in restoration and mitigation of the effects of global changes. [ABSTRACT FROM AUTHOR]

Aim: Vegetation types of Mediterranean thermophilous pine forests dominated by Pinusbrutia, Pinushalepensis, Pinuspinaster and Pinuspinea were studied in various areas. However, a comprehensive formal vegetation classification of these forests based on a detailed data analysis has never been developed. Our aim is to provide the first broad‐scale classification of these pine forests based on a large data set of vegetation plots. Location: Southern Europe, North Africa, Levant, Anatolia, Crimea and the Caucasus. Methods: We prepared a data set of European and Mediterranean pine forest vegetation plots. We selected 7,277 plots dominated by the cold‐sensitive Mediterranean pine species Pinusbrutia, Pinus halepensis, Pinus pinaster and Pinus pinea. We classified these plots using TWINSPAN, interpreted the ecologically and biogeographically homogeneous TWINSPAN clusters as alliances, and developed an expert system for automatic vegetation classification at the class, order and alliance levels. Results: We described Pineteahalepensis as a new class for the Mediterranean lowland to submontane pine forests, included in the existing Pinetaliahalepensis order, and distinguished 12 alliances of native thermophilous pine forests, including four newly described and three informal groups merging supposedly native stands and old‐established plantations. The main gradients in species composition reflect elevational vegetation belts and the west–east, and partly north–south, biogeographical differences. Both temperature and precipitation seasonality co‐vary with these gradients. Conclusions: We provide the first formal classification at the order and alliance levels for all the Mediterranean thermophilous pine forests based on vegetation‐plot data. This classification includes traditional syntaxa, which have been critically revised, and a new class and four new alliances. We also outline a methodological workflow that might be useful for other vegetation classification syntheses. The expert system, which is jointly based on pine dominance and species composition, is a tool for applying this classification in research and nature conservation survey, monitoring and management. [ABSTRACT FROM AUTHOR]

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]