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The dynamics of the population of a steppe perennial Senecio macrophyllus M.BIEB. during xerothermic grassland overgrowing

100%

Czarnecka B.

Acta Societatis Botanicorum Poloniae

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2009

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tom 78

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nr 3

247-256

The study aimed to determine the long-term changes of the Senecio macrophyllus M.BIEB. population traits: the abundance, reproduction mode, individual fecundity, seed rain and recruitment of new genets in the course of xerothermic grassland overgrowing. The study had also the applied goal: to estimate the chances of "special care" species to survive in the changing environment without management regime for the maintenance of grassland. The model object was the island population of large-leaved ragwort on Biała Góra (the White Mountain) near Tomaszów Lubelski, South-East Poland. To achieve these aims I used the following sets of data: phytosociological relev,s made in plant communities in an interval of 16-18 years; repeated elaboration of the numbers and life-stage structure of the population, both by non-surface and surface method; observation of plants, life cycle in 50 labelled genets; population reproduction and seed rain amounts. The area of an open xerothermic grassland decreased due to the process of overgrowing by bushes which was accompanied by the increasing coverage of forest and meadow herbs as well as monocotyledons, mainly Brachypodium pinnatum and Calamagrostis epigejos. The abundance of the S. macrophyllus population noticable diminished. The flowering mode has been changing during years from an oscillation to a chaotic type which caused the significant decreasing of the individual fecundity, population reproduction and seed rain. In last years it was reflected in the interruption of juveniles’ recruitment.

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Habitat conditions of Sisymbrio-Stipetum capillate and Koelerio-Festucetum sulcatae steppe plant associations in the Ostoja Nidzianska specially protected area

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Misztal A., Zarzycki J., Bedla D.

Infrastruktura i Ekologia Terenów Wiejskich

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2015

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nr IV/3

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Application of steppe species in urban green areas

72%

Wieczorek J.

Annals of Warsaw Agricultural University. Horticulture (Landscape Architecture)

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2004

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tom 25

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Floral biology of Senecio macrophyllus M. Bieb. (Asteraceae), a rare Central European steppe plant

58%

Czarnecka B., Denisow B.

Acta Societatis Botanicorum Poloniae

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2014

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tom 83

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nr 1

Knowledge of the flowering phase and plant pollination ecology is very important for understanding the life history of long-lived perennials. In the case of rare species, the information may have implications for conservation practices. Our studies on flower morphology and blooming biology of the vulnerable plant Senecio macrophyllus M. BIEB. were conducted in situ (flowering, activity of insect visitors) in the largest population in SE Poland and in laboratory (light and scanning electron microscopy). The disc florets open diurnally with most intensive anthesis in the early afternoon and attract insect visitors with nectar and pollen. In highly protandrous disc florets, pollen viability decreases in time, whereas stigma receptivity increases. The upper part of the pistil forms a brush-like pollen presenter, covered with unicellular trichomes with chromoplasts. Pollen presentation lasts 4–11 hours per floret, and 8 days in a single head, the main function of which is to extend the availability of male gamets for reproduction. The number of florets per head, the head size, and the number of pollen grains produced per anther, and the pollen grain viability differed significantly between microsites. The finding indicates that, apart from the biotic factors, abiotic conditions may considerably influence generative reproduction of the species. In the study area, the principal visitors of S. macrophyllus flowers were Hymenoptera, with predominance of Apis mellifera (53.4% of visits). The remarkable share of butterflies (13.9%) recognized as the long-distance moving insects may improve the genetic variability of individuals within a fragmented population. A more detailed study is necessary to explain the role of insect visitors in effective pollination and in gene transfer between patches. The assessment of optimal conditions for the generative reproduction is fundamental for the in situ conservation of this rare species.

Ograniczanie wyników

2 Acta Societatis Botanicorum Poloniae

1 Annals of Warsaw Agricultural University. Horticulture (Landscape Architecture)

1 Infrastruktura i Ekologia Terenów Wiejskich

2 Czarnecka B.

1 Bedla D.

1 Denisow B.

1 Misztal A.

1 Wieczorek J.

1 Zarzycki J.

1 2015

1 2014

1 2009

1 2004

The dynamics of the population of a steppe perennial Senecio macrophyllus M.BIEB. during xerothermic grassland overgrowing

Habitat conditions of Sisymbrio-Stipetum capillate and Koelerio-Festucetum sulcatae steppe plant associations in the Ostoja Nidzianska specially protected area

Application of steppe species in urban green areas

Floral biology of Senecio macrophyllus M. Bieb. (Asteraceae), a rare Central European steppe plant