Сезонний ритм розвитку північноамериканських видів роду Crataegus L. в умовах Криворізького ботанічного саду НАН України

Abstract

Представлені результатати порівняльного вивчення сезонного ритму розвитку 27 північноамериканських видів та різновидів роду Crataegus L. в умовах Криворізького ботанічного саду НАН України. За відповідністю до кліматичних умов інтродукції на підставі інтегральної оцінки комплексу основних фенофаз досліджені види розподілені на 4 групи. Визначені найбільш перспективні види для широкого використання в степовій зоні України.

Представлены результаты сравнительного изучения сезонного ритма развития 27 североамериканских видов и разновидностей рода Crataegus L. в условиях Криворожского ботанического сада НАН Украины. За соответствием климатическим условиям интродукции по результатам интегральной оценки комплекса основных фенофаз исследованные виды разделены на 4 группы. Определены наиболее перспективные виды для широкого использования в cтепной зоне Украины.

Plant introducers use indices of growth and progress to estimate adaptation capabilities and stability of organisms under new conditions. The aim of our scientific paper is to ascertain whether phenological phases fit non-native area climate for North American species of genus Crataegus L. in the conditions of Kryvyi Rih urban agglomeration to outline prospects of their use in industrial centre located in steppe zone. The study focused on the analysis of seasonal rhythm of the progress of 27 North American species and varieties of genus Crataegus growing in the planting of Kryvyi Rih Botanical Garden of NAS of Ukraine over the period of 2002–2016. The hawthorns under analysis start their vegetation season in the third decade of March – the first decade of April when the daily temperatures are over 5оC. The beginning of blooming continues from the third decade of April till the second decade of May. The length of blooming depends on weather conditions and phylogenetic heredity, on average, it lasts for 6–9 days. The first ripe fruits appear in the first decade of July and the last at the end of September. The vegetation season finalizes depending on properties of a species or a variety, it lasts throughout September–October. We measured indices of phenological atypicality for each taxon to define whether phenophases of given hawthorns fit non-native area climate; these calculations were made by integral estimation of basic phenophases. The 8-pointed scale of G.N. Zaytsev which is formed by the Ф1-index magnitude allows us to divide the objects of analysis into 4 groups. The hawthorns of sections Crus-gallinae, Dilatatae, Intricatae, Macracanthae, Rotundifoliae, Silvicolae as well С. scabrida Sarg. var. dumbari of section Brainerdianae show the least magnitudes of atypicality, the value is 4–5 points. Progress cycle of these species is the most suitable to climatic conditions of the introduction area. The group with the value of 3 points is made up of hawthorns of sections Coccineae and Molles as well C. irrasa Sarg. of section Tenuifoliae and C. jonesae of sections Brainerdianae. The species of this group are able to grow in even colder climate conditions. The maximal indices of phenological atypicality (2 points) were measured for two species of section Douglasinae; these species originate from the area with the most contrasting condition as compared with the introduction area. These species are able to grow in even colder climate conditions but they suffer from arid climate of the steppe zone, so they may be used in plantings near water bodies only. 15-year-long observations of the season progress rhythm allowed us to divide 27 species and varieties into 4 groups according to the correlation of their phenophases with non-native area climate. The North American species collected in Kryvyi Rih Botanical Garden of NAS of Ukraine have acclimatized successfully and they show good long-term prospects for wide introduction under the conditions of the industrial city in the steppe zone of Ukraine, excluding two species of the section Douglasinae.