Phenology of North American maple trees in the conditions of the Mari El Republic

Abstract

The article contains the results of the 2014 - 2018 phenology observation over 6 maple tree species (Acer L.) with natural habitats in North America. The objects of research were plants of the Botanical garden-Institute of VSUT: A. negundo, A. pensylvanicum, A. rubrum, A. saccharinum, A. saccharum, A. spicatum. The studied maples began growing at the end of April – the first decade of May and ended in October. The first, in the first decade of May, bloomed A. saccharinum and A. rubrum. Later blooming species were characterized by a longer flowering period, the latest and longest flowering within 20 days was observed in A. spicatum. Despite the different periods of flowering, the fruits of different species ripened relatively amicably, in the second half of September. The longest vegetation period was found in A. saccharinum (169±2.1 days), and this species is characterized by late autumn leaf blooming. The greatest period of autumn leaf blooming, more than a month, was characterized by A. spicatum. The studied species can be used in landscaping of the Mari El Republic settlements as part of an additional assortment, with the exception of A. negundo, which is a weed plant. Despite the similar timing of the passage of many phenophases, the variety of maples morphological features (shape and size of leaves, flowers and fruits, bark color, etc.) allows them to be used for decorative purposes. During the study period, the earliest passage of most phenophases was recorded in 2016, and the latest in 2017 and 2018.