Populations of Laminaria hyperborea at various latitudes
In: Helgoländer Wissenschaftliche Meeresuntersuchungen. Biologische Anstalt Helgoland: Hamburg. ISSN 0017-9957, more Also appears in:Kinne, O.; Aurich, H. (Ed.) (1967). Vorträge und Diskussionen. Erstes Europäisches Symposion über Meeresbiologie = Papers and discussions. First European Symposium on Marine Biology = Rapports et discussions. Premier symposium européen sur biologie marine. European Marine Biology Symposia, 1. Helgoländer Wissenschaftliche Meeresuntersuchungen, 15(1-4). 669 pp., more |  |
| Abstract | 1. Populations of Laminaria hyperborea were sampled in the Isle of Man (54° N), the Bergen area (60° N) in south-west Norway and the Tromsø area (70° N) in north Norway.2. The age of each plant was determined through the observation of a median section of the base of the stipe and the fresh weight of the stipe taken as a measure of the production of primary and secondary stipe tissue by the plant.3. At 4 m below mid-tide there was a slight difference in stipe weights at a given age between exposed and relatively sheltered sites in the Isle of Man. Differences between those in the Isle of Man and those at exposed sites near Bergen and near Tromsø were also slight. The longevity of the plants was greater near Bergen however.4. At 14 m below mid-tide plants were slightly smaller than at 4 m in the Isle of Man and a population from the same depth in a highly exposed site near Bergen had similar stipes. Again, however, the longevity was greater near Bergen, resulting in some very much larger plants.5. At 33 m below mid-tide near Bergen plants were very much smaller than at 14 m.6. Plants very small for their age were encountered in the Isle of Man only at the entrance to caves, where breaking waves seemed to cause damage.7. The largest plants for their age were found in shallow water rapids near Bergen. The longevity of these was low, however.8. It is concluded that local conditions have as much effect on early growth rate as latitude. Greater differences occur in the ability to become established and in longevity over the range of latitude studied and south-west Norway appears favourable for these. |
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