Olenev Grigory V. RussiaEkaterinburgInstitute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, 202 8 Marta St., Yekaterinburg 620144, Russiaolenev@ipae.uran.ru Author's articles Vladimir G. Ishchenko (1938 – 2021) – in memory of a Yekaterinburg Petersburger