Issue № 2. 2021.

From the editorial board
Korosov A. V.	Rather Displays: 2234; Downloads: 1047;	3
Analytical review
Polyakova O., Semenov S.	Emergetic analysis and experience of its use for the assessment of anthropogenic and natural systems Displays: 3170; Downloads: 1212;	4 - 20
Мазанаева Л. Ф., Гичиханова У. А.	Состояние популяций средиземноморской черепахи Testudo graeca Linnaeus, 1758 (Testudinidae, Reptilia) в Дагестане Displays: 3356; Downloads: 1122;	21 - 37
Original research
Golovatyuk L. V., Zinchenko T. D., Shitikov V. K.	Spatial distribution of diversity in benthic communities of lotic systems in the Middle and Lower Volga region Displays: 3637; Downloads: 1469;	38 - 53
Derevenskaya O. Y., Gallyamova R.	Assessment of the restoration of the zooplankton community in lake Chishmyale after ecorehabilitation activities Displays: 3673; Downloads: 1302;	54 - 66
Morozov N. V., Ganiev I. M.	Techology of biological treatment of industrial waste water from used lubricating (motor) oils Displays: 3844; Downloads: 1237;	67 - 78
Snegin E., Barkhatov A., Snegina E.	Peculiarities of nutrition of the lake frog (Pelophylax ridibundus Pallas, 1771) in the urbanized territory of the city of Belgorod (Russia) Displays: 3465; Downloads: 1175;	79 - 87
Tatarinov A. G., Kulakova O. I.	Species composition and structure of population of butterflies (Lepidoptera, Papilionоidea) in the Nechkinsky national park (Udmurt Republic) Displays: 7466; Downloads: 1166;	88 - 101
Methods of ecological investigations
Rumyantsev D. E., Frolova V. A.	The problem of diagnosing the accident rate of trees in an urban environment Displays: 5813; Downloads: 1251;	102 - 119
Synopsis
Gorbach V.	A practical introduction to the R Displays: 2878; Downloads: 1210;	120 - 122