Abstract
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 quarter, 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.
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Abbreviations
- AUC:
-
Area under the curve
- GBIF:
-
Global biodiversity information facility
- Maxent:
-
Maximum entropy model
- NFI:
-
National forest inventory of Georgia
- WWF:
-
World wildlife fund
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Acknowledgements
This research (PhDF 18-723) has been supported by the Shota Rustaveli National Science Foundation of Georgia (SRNSFG). We would like to thank Prof. Otar Abdaladze for the valuable recommendations and help provided during the fieldwork activities in Kazbegi region. Our special thanks to Maka Kikvidze for providing herbarium materials. We are thankful to Dr. Mariam Gabelaia for providing the comments on earlier versions of the manuscript. We are also grateful to Prof. Levan Mumladze for the suggestions and recommendations made.
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Akobia, I., Janiashvili, Z., Metreveli, V. et al. Modelling the potential distribution of subalpine birches (Betula spp.) in the Caucasus. COMMUNITY ECOLOGY 23, 209–218 (2022). https://doi.org/10.1007/s42974-022-00097-4
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DOI: https://doi.org/10.1007/s42974-022-00097-4