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.

摘要

这项调查的目的是研究三个卡布迪亚岛（突尼斯东部）的土壤和陆地植物。在2017年3月进行了采样。还测量了土壤的质地，盐度，pH和水分。根据Braun-Blanquet方法，共进行了180项植物相关记录。统计排序方法（聚集层次聚类，规范对应分析和SIMPER程序）用于识别植物关联。结果表明，除了大岛东北部的土壤为沙壤土外，土壤都是沙质的。在采样点（44个物种，22个科）中发现了高植物多样性。它们主要是盐生植物，嗜吸植物或嗜氮植物。这项研究使我们能够区分三个植物关联：Halimiono portulacoidis-Suaedetum verae位于一个有限的区域（加塔亚东北部），Salsolo-Cakiletum maritimae位于加塔亚和Djebel沙质海岸的东侧，占优势的Arthrocnemo macrostachyi-Halocnemetum cruciati位于约80％的胰岛中。我们的结果表明，土壤成分，盐分，水含量，pH值，海洋和海鸟的活动影响这些小岛中植物群落的多样性和分布。