Dynamics of species diversity of the small mammal community in slope larch forests of Northern Coast of the Sea of Okhotsk
E. A. DUBININ
Institute of Biological Problems of the North of FEB RAS, Magadan, Russia
Keywords: small mammals, population dynamics, community, species diversity, Northern coast of the Sea of Okhotsk
Abstract
In 2010-2023 the dynamics of population numbers and changes in the share of species in the community of small mammals (insectivores and rodents) inhabiting a slope larch forest in the vicinity of Magadan (Northern Coast of the Sea of Okhotsk) were traced. Сensuses of animals were carried out using trap-line methods, using Gero traps and cones. A total of 4.700 trap-days and 15.720 cone-days were worked. 3.384 individuals of 9 species belonging to the families of shrews (Soricidae), squirrels (Sciuridae), mice (Muridae) and hamsters (Cricetidae) were caught. During the period under review, the relative abundance and the amplitude of its interannual fluctuations decreased in the populations of the equal-toothed shrew (Sorex isodon) and the red-gray vole (Craseomys rufocanus). The shares of the Laxmann’s shrew (S. caecutiens) and the East Asian wood mouse (Apodemus peninsulae) in the community increased by 2.6 and 2.5 times, respectively, while simultaneously decreasing in the equal-toothed shrew by 2.8 times and in the red-gray vole by 3 times. As a result, about 50 % of the individuals in the samples began to belong to the Laxmann’s shrew and about 30 % to the red-backed vole (Clethrionomys rutilus). This, in turn, led to increased dominance (the Simpson index increased from 0.21 to 0.34), a decrease in evenness (the Pielou index decreased from 0.87 to 0.61) and a significant decrease in the species diversity of the small mammal community (the Shannon Index decreased from 1.7 to 1.3; t = 10.90, p < 0.001).
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