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  • Author: Magdalena Szymura x
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Abstract

Correlations between the morphology and cytology of invasive species and the effectiveness of invasion are among the most interesting questions in invasion ecology. Amongst exceptionally successful worldwide plant invaders, species of goldenrod (Solidago and Euthamia) are considered. The main aim of the study was to compare the morphology (concerning life traits) and cytology of the selected goldenrods occurring in south-western Poland with the effectiveness of their invasion. The results of the study, conducted in south-western Poland, showed that life traits of invasive Solidago and Euthamia taxa were clearly not connected with the effectiveness of invasion. The most widespread species, S. gigantea and S. altissima, had the highest ramets and uncommon species such as Euthamia graminifolia and S. virgaurea had short ramets. However, S. canadensis, which is tall, is also uncommon. The most frequent species (S. gigantea) produced smaller inflorescence than less frequent species (S. altissima, S. canadensis and Euthamia graminifolia). The spread of particular taxa was also not connected with the ploidy level and DNA content.

Aesthetic aspects of plant communities of ruderal urban sites in Szczecin

Synanthropization of plant cover, connected with urban development, contributes to the appearance of specialized ruderal plant communities, adapted to habitats exposed to human influence. A lot of published data have focused on urban flora, but the aesthetic aspect of perennial and temporary plant communities at urban sites has been frequently omitted. Currently the practical use of such plant communities is limited by the lack of descriptive information available. In this study great attention has been paid to variability of urban communities, defined by: aesthetic aspects, flowering period, and colour variability in flowering communities. In Szczecin, Artemisio-Tanacetetum vulgaris, Calamagrostietum epigeji, Dauco-Picridetum hieracioidis, and Rudbeckio-Solidaginetum have been recognized as especially decorative. They could be used to reduce the costs of establishing and maintaining urban green areas.

Summary

Study aim: running economy (RE) is important indicator of endurance performance. During puberty dynamic changes in body composition and function are observed, as such RE is also expected to change. The aim of the study was to compare the running economy (RE) in overweight and normoweight boys during a running exercise performed with constant velocity, and the assessment of changes in RE during puberty.

Material and methods: the RE of the subjects was evaluated twice: at the age of 11–12 and two years later. 18 overweight and 17 normal weight boys performed a graded test and a week later a submaximal run on a mechanical treadmill. During the exercise, physiological variables (oxygen uptake, heart rate, pulmonary ventilation, tidal volume and breathing frequency) were measured.

Results: the intensity of work in both tests (%VO2max, %HRmax) was significantly higher in the overweight boys and decreased with age (non significantly) in both groups. The physiological response during the run in the overweight boys was significantly higher compared to normal weight. When the oxygen uptake was expressed as VO2.BM–0.75, the RE was similar in normal weight and overweight boys. During puberty, the inter-group differences in the metabolic cost of work stay at a relatively stable level.

Conclusions: the lowered endurance performance in the overweight boys during puberty remains unchanged. The changes in physiological variables during puberty in both groups occurred in a similar way – the body composition did not influence the course of these changes in puberty.