Phytogeography of upwelling areas in the Arabian Sea
Schils, T.; Coppejans, E. (2003). Phytogeography of upwelling areas in the Arabian Sea, in: Schils, T. Mariene plantengemeenschappen in opwellingsgebieden van de Arabische Zee: een taxonomische, ecologische en biogeografische case study naar de mariene flora van de Socotra Archipel (Jemen) en het eiland Masirah (Oman) = Marine plant communities of upwelling areas within the Arabian Sea: a taxonomic, ecological and biogeographic case study on the marine flora of the Socotra archipelago (Yemen) and Masirah Island (Oman). pp. 109-130
In: Schils, T. (2003). Mariene plantengemeenschappen in opwellingsgebieden van de Arabische Zee: een taxonomische, ecologische en biogeografische case study naar de mariene flora van de Socotra Archipel (Jemen) en het eiland Masirah (Oman) = Marine plant communities of upwelling areas within the Arabian Sea: a taxonomic, ecological and biogeographic case study on the marine flora of the Socotra archipelago (Yemen) and Masirah Island (Oman). PhD Thesis. Gent University: Gent. 147 pp., meer
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| Author keywords |
Arabian Sea; biogeography; ecology; macroalgae; Masirah Island; northern Indian Ocean; seagrass; seaweed; Socotra Archipelago |
| Abstract |
Aim: Comparing the marine plant communities of two islands, with a similar diversity in biotopes, in two different upwelling areas of the Arabian Sea. Location: Arabian Sea: (1) the Socotra Archipelago (Yemen; 12.47°N, 53.87°E) in the Somali upwelling area, (2) Masirah Island (Oman; 20.42°N, 58.79°E) in the upwelling area of the southern Arabian Peninsula. Methods: The marine flora of different biotopes around both islands were examined by means of qualitative assessments. Ordination analysis (DCA) was used to identify the different plant communities and to correlate these with environmental parameters. The species composition of the identified communities were compared (tripartite similarity index) and their biogeographic affinity with nations bordering the Indian Ocean was determined. Indicator species analyses were performed to identify the characteristic species of the different plant communities and their biotopes. Results: The DCA analysis shows a clustering of sites (plant communities) corresponding with their geographic position, linked in turn to the prevailing environmental conditions of the different coastal areas. The combined interpretation of the ordination, similarity and biogeographic analyses results in the aggregation of similar plant communities of both upwelling areas into four biotopes. Main Conclusions: The north coast communities of Socotra and the west coast communities of Masirah can be grouped into 3 biotopes related to the degree of exposure and sedimentation. These biotopes are typified by indicator species, characteristic for specific substrata, and have a high biogeographic affinity with the East African coast. The plant communities of Socotra’s south coast and Masirah’s east coast constitute a fourth biotope, being diverse and species rich, typified by a large proportion of red macroalgae including the characteristic species of the unique Arabian Sea flora. This biotope has a pronounced biogeographic affinity with distant regions (disjunctly distributed taxa). Within the different biotopes, the communities of Masirah are more divergent from an East African flora in comparison to Socotra, the latter being a stepping stone between the East African and Arabian Sea flora. |
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