Umfang:
223 S.
Ausgabe:
Mikrofilm-Ausg. Ann Arbor, Mich. Univ. Microfilms Internat. 1981 1 Mikrofilm : 35 mm [Mikrofilm-Ausg.]
Inhalt:
Shallow water Antarctic benthic marine communities are composed primarily of trophic generalists that consume relatively unstable food items. Trophic specialists ingest more stable trophic resources or process adaptations that decrease their dependence on a food item when it is least abundant. Both generalists and specialists can be divided into groups or blocks of species, each block possessing similar adaptations for dealing with the trophic resource regime. Potentially competitive interactions are confined to within these blocks, there being few interblock interactions. This may increase community stability. When the potential for competition is greatest, species within these blocks change, cease feeding or otherwise alter their feeding ecology, thereby, decreasing the potential for competition. This has been termed "decoupling". It is argued that decoupling increases community stability. Benthic trophic resources, including organic detritus and macroalgae, are found to be more stable through time than previously believed. This may explain why the majority of polar species produce non-planktonic larvae or are viviporous. It may also account for the large number of organisms that reproduce during the austral winter. Low species diversity in polar systems is probably the result of several factors, including the Antarctic Convergence which prevents invasion by homogeneity of the Antartic province as a whole and the need to decrease the potential for competition (a destabilizing force) which prevents the evolution of finer niche partitioning.
Anmerkung:
Davis, Calif, Univ. of California, Diss., 1980
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Mikrofilm-Ausg.:
Sprache:
Englisch
