General Ecology of the
ABSTRACT. The Canadian Arctic marine flora is basically a regional extension of Atlantic species. As the extreme environmental conditions of low temperature, low salinity and long periods of darkness intensify towards the western and northern parts of the Canadian Arctic, there is a marked reduction...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1037.1945 http://pubs.aina.ucalgary.ca/arctic/Arctic26-1-32.pdf |
| Summary: | ABSTRACT. The Canadian Arctic marine flora is basically a regional extension of Atlantic species. As the extreme environmental conditions of low temperature, low salinity and long periods of darkness intensify towards the western and northern parts of the Canadian Arctic, there is a marked reduction in the number of species. The protective cover of sea ice, together with the seasonal development of a low salinity layer from ice melt, hinders mixing between water layers, and nutrient replenishment is apparently a critical problem. Communities are generally small and isolated largely because of substrate limitations. A population may be extensive and dense, but this is attributed to the small number of species and the relative ineffectiveness of most of these in competing for the available space. Following seasonal ice melt, the intertidal habitat in colder regions remains unsuitable for algal growth, because of its exposure to a combination of adverse climatic and oceanographic conditions. The decreasing diversity of species, as the physical conditions become more adverse, together with the nearly complete absence of endemics, indicate a low level of adaptation, and the arctic communities are judged to be ecologically immature. RÉSUMÉ: Écologie générale des algues marines benthiques de l'Arctique canadien. Fondamentalement, la flore marine du Canada arctique est une extension régionale d'espèces atlantiques. A mesure que les conditions de basse température, de faible salinité et de longues périodes d'obscurité s'intensifient vers l'ouest et le nord de l'Arctique canadien, il se produit une réduction marquée dans le nombre des espèces. La couche protectrice de glace de mer et le développement saisonnier d'une couche de faible salinité par suite de la fonte de la glace, nuit au mélange des couches d'eau, et le renouvellement des Cléments nutritifs est apparemment un problème critique. Les communautés sont généralement petites et isolées, surtout à cause des limitations du substrat. Une population peut être étendue ... |
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