Spatial patterns and floristic composition of plant communities in uninhabited islets: the case of Kaboudia (Chebba, Eastern Tunisia)

Abstract

The aim of this survey was to study soil and terrestrial plants in the three Kaboudia islets (eastern Tunisia). Sampling was conducted during March 2017. Texture, salinity, pH and water content of soil were also measured. A total of 180 relevés of plants were conducted according to Braun-Blanquet methods. Statistical ordination methods (Agglomerative Hierarchical Clustering, Canonical Correspondence Analysis and SIMPER procedure) were used to identify plant associations. Results showed that the soil is sandy except in the north-eastern part of the large islet where the soil is sandy-loamy. High botanical diversity is found in sampling sites (44 species, 22 families). They are mainly halophytic, psammophilous or nitrophilous plants. This study allowed us to distinguish three plant associations: Halimiono portulacoidis–Suaedetum verae in a limited zone (northeast of Gattaya), Salsolo–Cakiletum maritimae in east side of sandy coasts of Gattaya and Djebel and the dominant Arthrocnemo macrostachyi–Halocnemetum cruciati in about 80% of islets. Our results show that soil composition, salinity, water content, pH, the action of the sea and seabirds influence the diversity and distribution of plant communities in these islets.

Keywords:

• Soil
• phytosociology
• halophytes
• Kaboudia islets
• Tunisia

Acknowledgements

The authors wish to thank editors of Plant Biosystems, and reviewers for their comments which improved the quality of the paper. We also thank Ridha Ben Salem for the support during the sampling and Dr. Fatma Belaiba for English correction.

Disclosure statement

No potential conflict of interest was reported by the authors.