Faunistic problems of the retransforming territory

O. Kotlyarov
SSSIE “Chornobyl Radioecological Center”, Chornobyl, Ukrain

Contemporary territory of the Chornobyl Exclusion Zone (EZ) suffered ecological changes long before the nuclear disaster of 1986. The most essential have complied within the beginning of the starting-up works on the atomic station’s building: the growing of population, development of infrastructure, wood’s felling, natural landscape’s transformations etc. An anthropogenic influence on the most EZ ecosystems after the catastrophe was removed. Changes, made by the people, are rendered far enough significant that originally was difficult to predict uniquely a fate of separate species and ecosystems. One of the suggestions was the processes of ecosystem element’s reabilitation (autoreabilitation) will go in spite of the radiation contamination. The nature has chosen a single decision: recovering a variety of animal’s species and number (Balashov et al., 1999; Gaschak et al., 2000).
Selective winter-springtime (2001) stock-takings have confirmed the assertion in reconstruction of sufficiently hight quantity of birds, great and average mammals among the different aboriginal and installed species. Theoretical calculations of the main large predator’s number (wolf, fox) proved correct. The number of wolf is optimum and does not require for its adjustment the interference on the part of the man. Its main function on the EZ’s territory (appr. 46000 sq km with Byelorussian part) is the regulation of the ungulate’s number as well as more small predators. It’s significant during 15 years no ungulate’s substantial number reduction was registered and flashes of rabies (fox) as well. Although, the peak of the main vertebrate’s number was reached during the medium-end of 90-th. It’s possible to define the modern state of their number as a phase of stable cyclic and level that as protected.
Concept of radioautoreabilitation on the EZ’s territory expects to reduce at most the mobility of radioactive isotopes with its conversion in the bound condition. However environment remaking activity of the biotic members is at variance with this conception. Only visible part of activity reveals itself on the area of many thousands hectares. For example, the wild pig’s and beaver’s activity on marshy and flood-lands areas causes certain trouble , but its results are presented, sooner, theoretically. Different animals exercise significant influence on vegetation, preventing renewal a wood and slowing afforestation of an openned areas.
Soon after the disaster the natural reconstruction of rare and disappearing species, which are saved on protected territories basically outside of EZ, has begun. This phenomena has caused a variety of suggestions and exploitings as to the possible artificial increase in so called biodiversity by installing of earlier vanished species: a wisent, a brown bear, an european mink, Prjewalski’s wild horse (Pwh) etc. Even superficial consideration of reintroductional questions demostrates lack of prospects of such venturs. One example: american mink. How to withdraw it from the EZ’s territory while it presents outside the EZ? What must be done with the muskrat, which number is checking by the mink? What is the reproductive potential of two species? What will be in the future with the already formed chain: an american mink — a muskrat — a water vole? These questions generate other new strictly. So far the Pwh’s introduction’s project marketed (that is not full). However 3 years is too shirt period to consider an acclimatization successful: Pwh’s future and consequences for EZ are not clear. Nevertheless, it’s well known: introductional experiments(directed or casual) brought material and moral losses in its majority. The breach of the dynamic balance in EZ’s ecosystems will bring about sad consequences inevitable.

Zoocenosis — 2001
 Структура і функціональна роль тваринного населення в природних та трансформованих екосистемах: Тези I міжнародної конференції, 17-20 вересня 2001. – Дніпропетровськ: ДНУ, 2001. – С. 158-159.