Population characteristic of tundra vole in radioecological studies : Популяционная характеристика полёвки-экономки в радиоэкологических исследованиях

• Published in: Theoretical and Applied Ecology
• Main Authors: Ermakova, O.V., Raskosha, O.V.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Theoretical and Applied Ecology 2019
• Subjects: Ukhta; Tundra
• Online Access: https://dx.doi.org/10.25750/1995-4301-2019-2-101-107; http://envjournal.ru/ari/v2019/v2/19212.pdf

Different changes in certain demographic and morpho-physiological parameters of tundra voles (Аlexandromys oeconomus Pall.) at different stages of the population cycle were found as a result of long-term (1981–2018) radioecological studies of two isolated nature populations, living in the areas with similar ecology and different level (by one or two orders of magnitude) of natural radioactivity (Ukhta district of the Komi Republic). We used sex-age structure of the populations, reproduction level and certain morphological and physiological parameters (weight of vole, absolute and relative weight of adrenal glands, heart and liver) as the marker traits. Since 80-s, more animals have been noted at the contaminated site at all stages of the population cycle, and the number of individuals have been changed synchronously. Increase in the body weight and later reproduction of current year voles are followed by decrease in the functional activity of thyroid gland and chronic stress of adrenal function in voles at the contaminated site. Fluctuations of body weight and adrenal index in voles matched with changes in number of voles and may be used as relevant indicators of population state. In animals from the contaminated sites, high fertility compensates the increased mortality of young voles and contributes to the conservation of the population. “Radiation stimulation” occurs also as increased reproduction intensity, potential and total fertility, and accelerated maturation of follicles in the ovary. Our study and literature survey reveal that periodic ups and downs in the number of mouse-like rodents may be a result of changes in the population traits indicating significant changes in the organism of the animals forming population at the different stages. Ionizing irradiation had a modifying effect on the state of morpho-physiological and demographic parameters and the reproduction of tundra voles under the radioactive contamination. Irradiation could also strengthen the influence of intrapopulation processes. : В результате многолетних радиоэкологических исследований (1981–2018 гг.) на примере изолированных друг от друга природных популяций полёвки-экономки (Аlexandromys oeconomus Pall.), обитающей на территориях, сходных по экологическим условиям существования вида и отличающихся по уровню естественного радиационного фона на один-два порядка (Ухтинский район Республика Коми), показано неодинаковое изменение некоторых демографических и морфофизиологических показателей в разные фазы популяционного цикла. В качестве показателей использованы половозрастная структура популяций, уровень воспроизводства и морфофизиологические показатели (масса тела, абсолютный и относительный вес надпочечников, сердца и печени). Обнаружено, что ионизирующее излучение оказывает модифицирующее действие на состояние морфофизиологических и демографических параметров, показатели размножения полёвок-экономок в условиях радиоактивного загрязнения среды обитания и способно усиливать влияние внутрипопуляционных процессов.