Uwagi o znaczeniu badań produkcji ekosystemów wodnych oraz ich organizacji w ramach Międzynarodowego Programu Biologicznego

Streszczenie w języku angielskim

Strony 117-122 ; 24 cm

Abstract in English

The paper was read as the opening address at the conference on co-ordination of studies of the productivity of warter ecosystems (Olsztyn, 3-4 May, 1966) organized by the Productivity of Freshwater Ecosystems Section of the Polish Committee of the International Biological Programme. The aim of the conference was to discuss and reach an agreement on methods of collecting and elaborating material for calculation of production and the ways themselves of calculating production. The use of prioduction instead of biomass or abundance gives a better description of biological processes and permits of better comparison of very different groups of organisms, which in turn makes it possible to analyse the channels through which energy flows and ecological effectiveness. It is of course obvious that in addition to the estimation itself of production it is essential, in order to understand its regularities in different situations, to analyse the biotic and abiotic factors determining the channels of flow of energy and ecological effectiveness. With the present scanty knowledge available of the rules of production, even a very approximate way of assessing production is valuable. Reliable collection of material is of fundamental importance. The actual calculation methods, often imperfect, are continually being improved and at the same time also simplified. It is essential to express production in comparable units, convertible to the most universal units, calories. It is also essential to calculate production per unit of area of the body of water (and not only, e.g., per unit of volume or weight of substrate); only this way comparison of different bodies of water ecosystems can be attained. Production of ecosystems may be investigated in ways varying in degree of detail: 1) only on ,,entry” and ,,exit” (primary production and influx of allochthonous substance on the one hand, and outlow of organisms and deposition of sediments on the other); 2) assessment of production of all trophic levels; 3) estimation of the production of all trophic levels based on analysis of factors determining production (habitat, quantity and quality of food, competition, predation etc.). Even investigations of the first degree, carried out on a large number of waters, may at the present stage of our knowledge supply much valuable information. Particularly interesting prospects are afforded by analysis of situations in which the ecosystem is subjected to intervention of some kind, such as artificial mixing heating of the water, fertilisation, acclimatisation and introduction of organisms etc. It would then be easier to discover the rules governing production, and at the same time to indicate the possibilities of directing the production. The final part of the article contains a discussion of research on production from the organization aspect, under the International Biological Programme.

Pages 117-122 ; 24 cm