Factors affecting seaweed biogeographical and ecological trends along the Namibian coast
Engledow, H. R. ; Bolton, J. J. (2003). Factors affecting seaweed biogeographical and ecological trends along the Namibian coast, in: Proceedings of the XVIIth International Seaweed Symposium, Cape Town 2001. pp. 285-291
In: (2003). Proceedings of the XVIIth International Seaweed Symposium, Cape Town 2001. Oxford University Press: [s.l.]. , meer
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| Trefwoord |
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| Author keywords |
Namibia; biogeography; sand |
| Abstract |
Namibia forms the northern part of the Benguela marine province in south-western Africa. A splitting of the province into two sub-provinces has been proposed on zoogeographical evidence. This split is the result of decreasing species diversity in the northern regions, and is therefore not a taxonomic division. A number of factors have been found to affect seaweed biogeography on the Namibian coast, e.g. temperature factors, habitat availability and heterogeneity, sand inundation, etc. These factors also have an effect the local occurrence and abundance of certain species. Biomass sampling quadrats were taken at regular intervals up the shore and the species composition determined. Southern Namibia is separated from northern and central Namibia, due to the dominance of different species. Southern and northern Namibia had a greater horizontal spread on the primary axis of the DCA analysis, reflecting their greater habitat availability and heterogeneity. The shores of central Namibia, in contrast, exhibit minimal variation between shores. The difference between southern and central Namibia is an ecological shift brought about by an increase in temperature in the northern regions and a relatively high degree of sand inundation. The latter has resulted in the dominance of sand-tolerant species. As a result, the sub-province is an ecological entity rather than a floristic one. |
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