Dynamics of seasonal changes in introduced plants in Eastern Transbaikalia

Abstract

The article presents a comparative analysis of the seasonal development of introduced plants in the weather conditions of Eastern Transbaikalia for the growing periods from 2014 to 2019. The results presented are taken from 6-year phenological observations conducted in the arboretum of the Institute of Natural Resources, Ecology and Cryology SB RAS. We constructed the phenological spectra of the studied objects by year. We studied the main phenological indicators of vegetation the East Asian forest-steppe and Manchurian-Daurian preboreal species. We analyzed the meteorological data: the mean daily air temperatures and precipitation for the months of the growing season (2014–2019), and the sum of active temperatures and precipitation for this period. The data on the dynamics of the development of shrubby plant species in conditions of Eastern Transbaikalia for 2014–2019 indicate that plants respond adaptively to changes in weather conditions. Hereditary and physiological characteristics showed that the introduced plants are characterized as cold-resistant and drought-resistant. Corylus heterophylla and Armeniaca sibirica are most sensitive to temperature extremes in spring, in contrast to Euonymus maackii, which were stable. Low above-zero air temperatures in spring and a large amount of precipitation encourage plants to pass the development stages (phenophases) faster than in dry and warm weather (Corylus heterophylla, Armeniaca sibirica). At the same time, low temperatures (frosts) in spring with a wet period at the time of flowering negatively affect the further fruit formation in Corylus heterophylla individuals. Rainy or cloudy days reduce the color intensity of the autumn leaves, and cool, dry, and sunny weather contributes to the autumn color scheme. Armeniaca sibirica and Corylus heterophylla are variable in terms of the onset of the main phenophases; individuals of the Euonymus maackii species have minimal individual variability. The longest growing seasons on the phenological spectrum were registered in 2014 and 2018–2019 (in Corylus heterophylla individuals – 190 days), which contributes to the accumulation of more phytomass. The shortest growing season was registered in 2015 (Armeniaca sibirica – 150 days).