Graph model of interaction of anthropogenic and biotic factors for the productivity of the Caspian Sea

A. Yu. Perevaryukha

Vestnik Samarskogo universiteta. Estestvennonaučnaâ seriâ, no. 10 (2015), pp. 181-198

Résumé

In this paper the construction of the graph model, structuring multivariate analytical reports on the interaction of natural and anthropogenic factors in the ecosystem, which were presented in the form of a set of related concepts is presented. In the signed directed graph in the computing environment a propagation of pulses from the vertices within the context the study the situation of degradation of sturgeon stocks of the Caspian Sea was analyzed. These species are included in the Red Book since 2010 despite efforts in organizing an artificial breeding of fish. Method of cognitive structurization allowed to reveal hidden feedback loop on the basis of the graph, weakens the reproduction of fish populations and become the cause of overestimation acceptable exploitation of bioresources. An approach of functional iteration for describing the dynamics of population processes with nonlinear function of the efficiency of reproduction was discussed. It is shown that the discrete iteration have contradictory qualitative behavior of the trajectory in terms of biological interpretation of bifurcations. It is proposed to use the predicative redefined computing structure based on the chart of behaviors for the description chain of regime changes of the simulated process. For this type of structural changes is promising to allocate substantial fluctuations of growth rate in the early ontogenesis of fish.

Détail

Keywords: graph models in ecology, cognitive structuring of factors, unstable population processes, interpretation of nonlinear effects.
Mots-clés : contours of influence