Functional organization of population as an approach to studies of population resistance. Applied aspect (small mammals as examples) [Review] [Russian]

摘要

The responses of 14 species of small mammals (marsupials - 1, insectivores - 2, and rodents - 11) to depopulation of local sites were studied. The restoration of some species populations proceeded in accord with breeding rates; in others, it occurred faster than it might be in breeding; reestablishing of some populations depended on situation. Functioning of local populations specifies the rate of settling free areas. In one case, the control of local density is provided, in another one, there is an excess of nonresidents responsible for high rates of the reestablislunent. These modes of functioning (controlling and reestablishing) arc considered as alternative ones (they cannot be realized at the same time). The controlling type of functioning is related to the stable composition of a local population and a relatively low share of nonresidents in a capture. The reestablishing type is related to the variable composition of a local population and a high share of nonresidents. The capability of species to form local populations (subunits) with different modes of functioning makes it possible to unite them into three groups. The first group includes the species capable of forming units of both types. Some species (subgroup a) can change the mode of functioning as a response to some disturbance. The species of this subgroup can change the functional structure of the population in space (portion of the population provided for one of the alternative functions). This phenomenon is considered as a nonspecific population response, which allows species to be adapted to negative environmental dynamics. Some species may change the mode of functioning in the course of the population cycle. They compose subgroup b. Species of this subgroup has different resistance to impacts at various phases of the population cycle. The species with the reestablishing function compose the second group, those with controlling one form the third group. The possibilities to use the species of different groups for indication of ecosystem status are considered. The classification of the species obtained may be useful for small mammal population control and prophylaxis of rodent born diseases.