Yury Kamenir
SIZE SPECTRA OF NATURAL AQUATIC COMMUNITIES
Through comparison of concepts of biogeochemical cycling, trophic pyramid, and living matter, a graph-analytical model of ecosystem (Ideal Minimal Ecosystem, IMES) was formulated. Spectral analysis was selected as one of the most effective approaches to study the structure and functioning of natural ecosystems. A possible method of this type (sets of size spectra and allometric equations) was proposed. Living Matter concept of V. Vernadsky was selected as a prospective methodology for ecosystem analysis. The first size spectra (SS) of living matter (i.e., all assemblage of living organisms of the ecosystem) were developed for the World Ocean, the Black Sea and some other natural ecosystems.
Through analysis of the IMES-model, a scheme of SS change in the course of ecosystem succession and degradation (e.g., under anthropogenic stress) was derived; the SS extremities were noted as highly important for analysis.
A statistical estimate of microbial biomass (mg ATP per unit area of the earth) was obtained by means of oceanic cruise works and analysis of published data.
Through comparative analysis of size spectra and allometries, surface of organisms (S) was evidenced as a better descriptor of their role in metabolic activity of integral community than traditionally used abundance (N) and biomass (B). Notion of metabolic surface (Sm; lungs, gills; leaves, roots) was introduced, and an allometric equation was calculated.
Through comparison of the IMES-model and the living vortex concept of G. Cuvier, theory of dissipative structures was selected as an effective tool for comparison and integration of models describing the structure of the water mass and the structure of the aquatic community inhabiting it.
Possible ways of use of scaling in ecological modeling and forecast were considered. A comparative analysis was done on the basis of original studies and previously published data encompassing the maximal possible range of ecosystem sizes.
The Integral Surface Index (ISI, some 104 m2 m-2, i.e. dimensionless value) was found via a comparison of aquatic communities in the maximal size range of ecosystems (from the World Ocean to a sealed microbial community).
The Lake Kinneret size spectra (BSS, NBS, TSS) provide empirical illustrations of the discussed methods and results.
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