The annotated checklist of plant species that occur in the wetland habitats of Georgia (the Caucasus)

Abstract The checklist includes 270 species that belong to 80 families and 183 genera. Each species has been annotated with the following information: life form, wetland indicator status, and location. In this checklist, Angiosperms are represented by 252 species (93.3%), Bryophytes – 10 species (3.7%), Pteridophytes – 8 (3%), Gymnosperms – 1 (0.4%). The largest families by the number of species are Cyperaceae – 39 (14.4%), Poaceae – 29 (10.7%), Rosaceae – 19 (7.1%), Asteraceae – 17 (6.3%), Fabaceae – 11 (4.1%) and Juncaceae – 11 (4.1%). The checklist is dominated by 55 Palaearctic species (20.4%), followed by 46 Holarctic (17.1%), 31 Euro-Mediterranean (11.5%), 31 Cosmopolitan (11.5%), and 27 Euro-Siberian (10.03%) species. The endemism rate is 4.8%, and the proportion of invasive and naturalized plants is 8.5%. Obligate wetland plants, mainly belonging to the families Cyperaceae and Juncaceae, make up 34.2% of the floristic composition. This is the first comprehensive published checklist of the flora of Georgian wetlands, annotated with wetland indicator values

Fine-scale analysis of habitat occupancy by Kura lizard (Darevskia portschinskii) and its daughter parthenogenetic form (Darevskia dahli)

Two species of rock lizards, the parthenogenetic D. dahli and the sexually reproducing D. portschinskii, coexist in a rocky outcrop in an area of ca. 1 ha, in the vicinity of Tbilisi, Georgia; the location has been well-known since the middle 1960s. The population density of the parthenogenetic lizard is five times higher than that of the sexual breeder. We studied the distribution of active lizards in space and time over three consecutive years, during the spring and autumn activity periods, to explore spatial and temporal differences between the species on a fine spatial scale. We studied the influence of temperature, humidity, and quantitative characteristics of the surface and the distance from permanent water source on the spatial distribution of D. dahli and D. portschinskii. Darevskia portschinskii was less dependent on the distance from the water source and more evenly distributed in space and time than D. dahli. Despite potential competitive interactions, the species did not avoid each other on the microhabitat scale, suggesting that the observed ecological differences are not caused by a niche shift. More individuals of the sexual breeder than individuals of the parthenogen were found in suboptimal habitats. This feature may increase the evolutionary success of D. portschinskii in a long-term perspective

Modelling the potential distribution of subalpine birches (Betula spp.) in the Caucasus

The treeline ecosystems in the Caucasus are mainly composed of birch (Betuletum) stands. These high-mountain forests encompass pivotal ecological functions like climate regulation, water retention, soil protection and more. The location of Caucasus birches as part of the treeline communities determines its vulnerability to anthropogenic as well as natural stressors. Therefore, the natural distribution area of birches has been significantly shrunk. Meanwhile, the two contrasting tendencies are also observable in the Caucasus, the lowering of the natural upper limit of the treeline border as well as the widening of the distribution area towards higher elevations. In this research, we aimed to model the actual distribution areas of Caucasus birches according to the factors and patterns of their present distribution. We used the Maxent (Maximum Entropy Model) model based on WorldClim bioclimatic variables—mean temperature of warmest quarter, mean temperature of coldest quar- ter, precipitation of coldest quarter and precipitation of warmest quarter, and 160 study plots (including 100 field experimental plots). The model demonstrated high predictive power AUC = 0.97. The Maxent algorithm showed the potential distribution areas of Caucasus birches covering the entire Caucasus region and the climatic variables as the main factors contributing to or limiting the distribution of birches in the study region. Understanding the distribution characteristics of birches in the Caucasus can serve as a basis for future research on shifts and changes in treeline forest communities occurring as a result of various impacts, e.g. climate change