Classification of forest and shrubland vegetation in Mediterranean Turkey

Abstract

Questions What are the main vegetation types of forest and shrubland vegetation at the alliance level in Mediterranean Turkey? What is their syntaxonomical position? Can we integrate them into the European vegetation classification system? Which environmental factors are the main drivers of the floristic differentiation of vegetation types? Location Southern and western Turkey. Methods We collected 4,717 vegetation plots of forest and shrubland vegetation in Mediterranean Turkey and performed an unsupervised classification of this data set. We described vegetation types based on the classification results, expert knowledge and information from the literature. We defined diagnostic species and prepared distribution maps for each vegetation type. To support the interpretation of the vegetation types, we determined the most important environmental variables using canonical correspondence analysis. Results The studied vegetation was divided into 21 types related to three vegetation belts: (a) thermo‐ and meso‐mediterranean, comprising coniferous (Pinus brutia, Pinus pinea) and sclerophyllous forests, as well as macchia, garrigue and phrygana; (b) supra‐mediterranean, comprising Pinus nigra subsp. pallasiana forests, thermophilous deciduous forests dominated by various oak species and Ostrya carpinifolia, and forests dominated by temperate species such as Fagus orientalis; and (c) oro‐mediterranean, comprising forests and shrublands dominated by Abies cilicica, Cedrus libani, Juniperus excelsa and Juniperus communis subsp. nana. Elevation was identified as the main environmental driver of the vegetation pattern. Among climatic variables, the most important are the mean temperatures (annual and of driest, coldest, and warmest quarters), minimum temperature of winter, precipitation of warmest and driest quarters and precipitation seasonality. These factors indicate the decreasing effect of the Mediterranean climate with increasing elevation. Conclusions The vegetation of Mediterranean Turkey is arranged along climatic gradients depending on elevation and the distance from the Mediterranean Sea. Most vegetation types in this area correspond to the syntaxa accepted in EuroVegChecklist, while others were described as new.

Classification of forest and shrubland vegetation in central and eastern Euxine Turkey and SW Georgia

“…Western and southern Anatolia is mainly dominated by Mediterranean vegetation, since these regions are under the effect of a Mediterranean climate. The syntaxonomy and synecology of forest and shrubland vegetation in these regions, based on numerical classification and ordination, was elaborated in detail by Kavgacı et al (2021). However, relict Mediterranean vegetation is also seen in northern Anatolia within the Euro-Siberian phytogeographical region.…”

“…andrachne, Laurus nobilis, Juniperus excelsa, Olea europea, Quercus coccifera, Sarcopoterium spinosum and deciduous forests of Carpinus orientalis are the typical representatives of Mediterranean vegetation in Euro-Siberian Turkey (Bonari et al, 2021;Kavgacı et al, 2021).…”

“…Pinus brutia and P. pinea exhibit an extensive distributional range in Mediterranean Turkey (Bonari et al, 2020;Kavgacı et al, 2021).…”

“…In some cases, we also integrated expert knowledge and information from the literature. In this context, the clusters dominated by the same tree species, appearing in similar ecological conditions, distributed in the same biogeographical pattern and therefore representing the same vegetation types, were merged (Kavgacı et al, 2021). Diagnostic species of each type were defined by calculating the fidelity of each species to each vegetation type (Chytrý et al, 2002) F I G U R E 1 Map of the Euxine province in northern Turkey and SW Georgia and border of the study area.…”

“…Due to the higher mountains in Colchis, there is a rapid transition from the Colchic vegetation to the Irano-Turanian phytogeographical region(Davis, 1965(Davis, -1985, unlike in central and western Euxine regions. The disappearance of Pinus nigra in Colchis is also clear evidence of the abrupt transition from the Euxine to the Irano-Turanian region, since it is a characteristic species of the transitional zone among Euro-Siberian, Irano-Turanian and Mediterranean phytogeographical regions in other parts of Anatolia(Çoban & Willner, 2019;Kavgacı et al, 2021).As a result of the elevational, biogeographical and macroclimatic vari-ations, seven main different vegetation groups were determined in central and eastern Euxine Turkey and SW Georgia: (1) relict Mediterranean forests and shrublands mainly appeared along the coastline, besides some inland localities; (2) lowland and submontane forests; (3) central Euxine mountain forests; (4) eastern Euxine (Colchic) mountain forests; (5) subeuxine forests; (6) azonal riparian forests; and (7) subalpine and alpine…”