Original paper
Vegetation patterns of a rapidly drying up salt lake ecosystem: Lake Urmia, NW Iran
Ghorbanalizadeh, Atefeh; Akhani, Hossein; Bergmeier, Erwin
Phytocoenologia Band 50 Heft 1 (2020), p. 1 - 46
108 references
published: Apr 28, 2020
published online: Jan 2, 2020
manuscript accepted: Aug 13, 2019
manuscript revision received: Jul 8, 2019
manuscript revision requested: Jun 26, 2019
manuscript received: Mar 9, 2019
ArtNo. ESP024005001000, Price: 29.00 €
Abstract
Questions: What are the plant communities and vegetation pattern on shorelines of a hypersaline desiccating lake and which environmental factors influence the zonation pattern of these communities? How is the species richness along salt and moisture gradients? Which plant communities and rare species are threatened by the impact of lake shrinkage? Which advice can be offered for the management and restoration of the area? Study area: Lake Urmia, NW Iran, one of the world’s largest saltwater lakes. Methods: We established 14 transects with 174 relevés in different parts of the lake and collected soil samples. TWINSPAN was used for vegetation classification and NMDS for ordination. Results: We distinguished 27 plant communities and described as new the associations Salicornio iranicae-Bolboschoenetum affinis, Tamaricetum octandrae, Salicornietum iranicae, Climacopteretum crassae, Suaedo altissimae-Climacopteretum crassae and the Atriplici leucocladae-Caroxyletum dendroidis. We present an overview of the syntaxa and illustrate typical zonation patterns of the lake’s salt marsh vegetation under current conditions of desiccation. Conclusions: The vegetation pattern and vegetation dynamics of the area is seriously affected by the hydrological changes around Lake Urmia. Fragmentation of wetland plant communities due to water shortage, increasing disturbance and invasion of ruderal species affect the floristic composition of the lakeside. Increasing soil salinity and decreasing moisture lead to area loss or even disappearance of certain plant communities. Plant communities with C4 annuals or pioneer ruderal species are developing or spreading in sites with low soil salinity or on sandy soils. We strongly recommend vegetation monitoring using permanent plots to improve the predictability of succession trends. Groundwater exploitation, unsustainable use of water resources in the catchment area, any further disturbance in the lakeside area including grazing and artificial plantation activities need to be prohibited. Taxonomic references: Flora Iranica (Rechinger 1963–2015), except Chenopodiaceae (Akhani et al. 2007) and other up-to-dates available in various papers and data bases as Euro-Med Checklist (Euro+Med Plantbase; http://www.emplantbase.org/home.html [accessed 1 September 2018]). Abbreviations: Comm. = Community; DOE = Department of Environment; ICPN = International Code of Phytosociological Nomenclature; NMDS = Non-metric Multi-Dimensional Scaling; TWINSPAN = Two-Way Indicator Species Analysis)
Keywords
Aridification • halophyte vegetation • hypersaline lake • Irano-Turanian region • lake desiccation • salinity gradient • saltmarsh flora