Specifics of the ontogenesis of Grindelia squarrosa in populations from eastern Ukraine
Results of studying of the ontomorphogenesis of the North American adventive species G. squarrosa in its secondary range in natural conditions of eastern Ukraine are presented. The scheme of ontomorphogenesis is given and age states are selected (seeds, seedlings (p), juvenile (j), immature (im), vi...
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| Format: | Article |
| Language: | English |
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National Museum of Natural History, National Academy of Sciences of Ukraine
2020-12-01
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| Series: | Geo&Bio |
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| Online Access: | http://museumkiev.org/public/visnyk/19_2020/gb1907-kucher.html |
| Summary: | Results of studying of the ontomorphogenesis of the North American adventive species G. squarrosa in its secondary range in natural conditions of eastern Ukraine are presented. The scheme of ontomorphogenesis is given and age states are selected (seeds, seedlings (p), juvenile (j), immature (im), virginal (v), young generative (g1), medieval generative (g2), aging (g3), subsenile and senile plants) and their characteristics are presented. It was found that the number of seedlings differs significantly during the growing season, the germination of seeds is also affected by temperature, the largest number of seedlings is observed at values from +25 to +27 C˚ in the spring. The choice of the study site is not accidental — the locality of the species in the Starobilsk grass-steppe meadow of Luhansk Oblast in the floodplain of the Siversky Donets River is one of the primary centres of deposition and distribution of G. squarrosa and its current high invasive status. The research was conducted according to the generally accepted methods of Zlobin at four localities. The density, ontogenetic and vitality structure of populations were studied. Each population was surveyed five times a year at the beginning (end of May) in the middle (June; early and late July) and at the end of the growing season (September). It was determined that the species is characterised by non-simultaneous germination of seeds and the formation of monodominant groups; the species acts as a co-dominant in steppe groups, prefers sandy loam and clayey loam and gravely soils, rarely occurs on gravel and dense clay substrate. The period of ontogenetic development of the studied species lasts 1–2 years. As a result of studying the ontogenetic structure of model populations of G. squarrosa, it was found that they are dominated by plants of pregenerative state, i.e. the spectrum of age groups is left-sided, characterised by positive asymmetry with peak on plants of younger age group, full-fledged populations and has high recovery indices.
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| ISSN: | 2617-6157 2617-6165 |