In: Phyton, 52 Fasc. 1 (2012), S. 73-99, with 6 figures

Key words: Khuzestan, Persian Gulf, flora of Iran, island flora. – Floristics, halophytes, conservation, phytogeography, vegetation.

Summary

AKHANI H. & DEIL U. 2012. First observations on the flora and vegetation of three islands in the NW Persian Gulf (Iran). – Phyton (Horn, Austria) 52 (1): 73–99, with 6 figures.

Dara, Booneh (Ghamar) and Ghabre Nakhoda are three small islands located in the Northwest of the Persian Gulf. So far there are no botanical records from Ghabre Nakhoda and Dara Islands, and only 16 species were known from Booneh island. The flora and vegetation of these islands was studied during three expeditions in 2010 and 2011. The vascular plant flora was documented by 121 herbarium specimens. The vegetation on Dara and Ghabre Nakhoda was analysed by transects and by vegetation mapping. On Booneh, 12 vegetation relevés were sampled. The flora is analysed according to life forms and phytogeographical elements and the vegetation is compared with other regions of the Persian Gulf.
In total 80 species of flowering plants were recorded on these islands, 20 on Ghabre Nakhoda, 52 on Dara and 64 on Booneh. Ghabre Nakhoda is the smallest island (3 hectares) with topsoil con-sisting of only shell particles. The vegetation is dominated by a dense annual turf with Malva parviflora, Calendula arvensis s. l. and Senecio glaucus and mosaics of small halophytic patches with Suaeda vermiculata and Halocnemum strobilaceum. Dara’s topsoil consists of sandy and silty sediments. It has a small-scale structured internal tidal zone with a mosaic of different halophyte communities. The sand dunes are colonized by Salsola rosmarinus and by an annual floor consisting of Launaea mucronata and Brassica tournefortii. The tidal muddy part is dominated by hyperhalo-phytes of succulent Chenopodiaceae. Booneh is the longest island (6.5 km length) with sandy and silty soils and muddy tidal areas. The vegetation types are very similar to Dara. On several islands, the annual halotolerant plant communities of the class Frankenietea pulverulentae are well devel-oped.
Phytogeographically the area is characterized by a mixture of Irano-Turanian, Saharo-Sindian and Mediterranean elements. The Mediterranean introgressions are related to the pronounced winter maximum of the precipitation and to the fact that the study area is not absolutely frost free. There-fore, many tropical elements recorded from the islands in the Strait of Hormuz are missing here. Flora and fauna of the non-habited and not grazed islands are valuable for the conservation of the biodiversity of the Near East. The islands should be protected also in respect to their avifaunistic relevance.