Biotopical distribution of sable in state nature reserve «Yuganskiy» area

Abstract

The population dynamics and biotope distribution of the sable (Martes zibellina) in the Yuganskiy nature reserve have been a subject of continuous study since 1988. Data for analysis is obtained from annual route census surveys performed in February and March. There are four major types of sable habitats: dark conifer taiga (primarily formed by Pinus sibirica, Abies sibirica and Picea obovata), light conifer taiga (forest stands dominated by Pinus sylvestris), deciduous taiga (secondary forests dominated by Betula and Populus, with conifers in the undergrowth) and raised bogs (poorly drained treeless or treed spaces covered by Sphagnum and dwarf forms of Pinus sylvestris).  Based on the material collected in 1988-2015 using the calculated biotope preference coefficient we defined the degree of attractiveness of different biotope types. In the area of the Yuganskiy nature reserve, forested biotopes are optimal for the sable. They represent its intrinsically typical biotopes where population density is defined by a complex of characteristic food and shelter conditions, as well as a variety of intrapopulational factors. Among the different types of forested habitats of the sable, the highest and most stable population values are typical for dark conifer taiga, which makes it a key biotope for the survival of the species’ population. This habitat type is also characterized by the maximum values of the biotope preference coefficient, which indicates the apparent preference of the sable among other mentioned biotope types. Light conifer and deciduous taiga are less valuable; however, they also provide sufficient conditions to ensure the stability of the sable population. In the Yuganskiy nature reserve, these two habitat types are equally attractive for sable populations, as shown by the virtually equal values of the preference coefficient and a similar type of its value dynamics. Bog biotopes are pessimal for the sable due to the scarcity of the ecological resources required by this species. They are characterized by the lowest population densities of the sable and the greatest population fluctuations from year to year. The biotope preference coefficient is often near zero, which also indicates the low attractiveness of these habitats.