Estimation of Parameters of Radiocapacity of Biota in Ecosystems; Criteria of Their Well-Being

1. Abstract

The history of the Chernobyl accidents knows many examples, where the behaviour radionuclides in ecosystems in an obvious way reflected the course and laws of ecological phenomena, this is for example this phenomenon of active washout of nuclides from the surface of the Dnieper reservoir, in particular, from territories of Chernobyl zone of 30 km, into the territory of Ukraine and Byelorussia. Rate and parameters of such drain (0,01–2 % in year for Cs-137 and 0,1% – 4 % in year for Sr-90), define themselves as fundamental drains characteristic for big ecosystems like the Dnieper reservoir areas. The dramatic example of those phenomena of sorbptioning and desorbption of radionuclides (especially for Cs-137) in the closure of a reservoir cooler, the Kiev water basin and other superficial reservoirs, reflects the fundamental hydrological properties of water ecosystems.

The following conclusion can be drawn. At any severe hydrological, biological and technological process in ecosystems polluted by radionuclides, an appreciable redistribution of radionuclides - tracers in biotic and a-biotic components ecosystems is observed. Also the inverse conclusion is possible therefrom. Therefore it is countable count that research of distribution and redistribution radionuclides on biotic and abiotic components of ecosystems may serve as an important tool to research of dynamics and to forecasting the condition of an ecosystems and its biota.

The theory of radiocapacity of ecosystems developed hereby has permitted to assess the integrated characteristics of radionuclides distribution in ecosystems, to establish laws of radioecological processes and to determine the location of increases of radionuclides in ecosystems. The theory and models of radiocapacity of ecosystems have allowed to define approaches to a substantiation of ecological specifications on permissible levels of pollution in an ecosystem and their elements, and to permissible dumps and radionuclides emissions in ecosystems [1–3].

Our researches on reliability of ecosystems have shown a line of parameters, such as a variety of type of ecosystems; of biota; of number of species in ecosystems and rate of duplication of species. They form eventually the necessary “integrated parameter”, suitable for an estimation of the general stability and reliability of ecosystems [2, 3, 4, 5].

The definition however of such parameter demands a huge amount of initial data on contributing parameters at different stages of the life of ecosystems. Already on noticeable changes of the status of the ecosystem an estimation of their well -being and reliability can be made. Clearly, when in ecosystem as a whole, the variety of species decreases, the biota, number and speed of duplication of dominant kinds is reduced, then it is not difficult to observe a damage and/or an oppression of ecosystems. Such affirmative research is useful, but it is not enough, as it does not allow the making of an outstripping forecast of the condition of ecosystems nor to offer counter-measures. Radiocapacity - a sensory characteristic for the plant ecosystem’s well-being is preferable. It is a non-dimensional quantity that characterises the part of radionuclides, which can be retained by the ecosystem without having deteriorated neither the whole system nor its parts. The only considerable effect on the ecosystem to be considered would the effect on the of radiocapacity rate factor. Separately, we based oneself on the theory, according to which the negative influence on the ecosystem would give rise to deterioration of its well-being; and, accordingly, - would be observe a reduction of the radiocapacity of the system. On the other hand, - the improvement of the ecosystems well-being would induce an increase of its of radiocapacity rate factor.