Phenospectrum of Black Alder (Alnus glutinosa Gaertn.) Plants in Ecotopes of the Central Part of Steppe Zone of European Russia

Abstract

In long-term studies (21–30 years in the floodplain ecotype and 12 years in the ecotype of sandy terraces), the duration of the main phenological phases of the development of black alder (Alnus glutinosa Gaertn.) plants was determined. The influence of the edaphic factor is manifested in the dates of the termination and duration of individual phenophases. In the sandy-terrace ecotype, growth buds are laid 8 days earlier, the leaves fall 2 weeks earlier, and the period of shoot development is longer than 7 days. Statistically significant differences between the ecotypes (t_f = 2.12–7.16 > t₉₅ = 2.01–2.03) were revealed in the duration of flowering periods and leaf development. In each ecotype, the strongest dependence of the phenological phase duration was revealed under the combined influence of the heat and moisture conditions of the corresponding period (r_{x (yz)} = 0.55–0.99). An identical phenological spectrum in the two studied ecotypes is observed in years with a 1.5- to 2.0-fold excess of the mean multiyear value of the hydrothermal coefficient.