In stressful environments, invasive plants acclimate more efficiently than native plants and hybridization mainly contributes to this process. We examined changes in the morphological characteristics, photosynthetic characteristics, and antioxidant capacity of Sphagneticola trilobata and its hybrids in a low-light environment to explore their invasiveness, with Sphagneticola calendulacea serving as the control. The morphological plasticity of S. trilobata was not dominant, the maximal photochemical efficiency of PSII, actual quantum yield of PSII, and electron transport rate of PSⅡ increased and nonphotochemical quenching decreased, while S. calendulacea and the hybrid produced opposite results. S. trilobata showed fewer spots stained for reactive oxygen species in tissues, with an increase in superoxide dismutase activity. Although S. trilobata is a heliophilous plant, we found that the shade tolerance of S. trilobata and the hybrid were stronger than that of S. calendulacea, which may be one important mechanism of invasion.
Článek přináší poznatky o vznikajících mezidruhových vztazích v ekosystémech po zavlečení nového invazního druhu rostliny – netýkavky žláznaté (Impatiens glandulifera) – a uvádí některé entomologické aspekty jejího masového výskytu v novém prostředí., The impact of aphids on the invasive plant Impatiens glandulifera in the Czech Republic is shown and some entomological aspects of I. glandulifera distribution in local ecosystems are discussed., and Petr Starý, Jan Havelka.
The invasion of Paulownia tomentosa (Paulowniaceae), a new alien tree species in Central Europe, native to China, is analysed. By using its distribution in Austria, the invasion of this country is analysed in detail. The first reports of P. tomentosa in Austria were in the 1960s in Vienna. Since then, the number of sites has increased exponentially, with a total of 151 sites in 27 grid cells of the Floristic Mapping project of Austria. The number of sites per grid cell is strongly positively correlated with the minimum residence time in grid cell, which explains 86% of the deviance in the general linear model (GLM). The localities are confined to warm lowland areas (below 450 m altitude) and are concentrated in cities, with 90% of all localities recorded in cities with > 100,000 inhabitants. Paulownia tomentosa typically occurs in small populations of less then 10 individuals (83% of all records) and behaves as a pioneer species colonizing mainly disturbed urban habitats. Near-natural habitats, e.g. forest clearings and riparian shrubberies are rarely colonized. In extremely disturbed areas, the average number of vascular plant species is low (8.9 species), as is total plant cover (17%). As P. tomentosa is currently mostly confined to synanthropic habitats in urban areas, the invasion is not yet a nature conservation issue. In the future, predicted climate change might allow P. tomentosa to spread beyond its current distribution. The habitat preference in the eastern USA indicates that further spread of P. tomentosa in Central Europe might be accompanied by a switch to more natural habitats, e.g. forest clearings and forest margins. Thus, the future spread of this species should be closely monitored.
Článek přináší informace o netýkavce žláznaté (Impatiens glandulifera, syn. I. roylei), jedné z nejznámějších zavlečených invazních rostlin na našem území. Nabízíme podrobnější pohled na její biologické vlastnosti, základní informace, jak se k nám tento druh dostal, a pokusíme se vysvětlit, proč se na našem území tak úspěšně šíří. Nastíníme i výhled dalšího možného vývoje., We provide information on the origin, biological characteristics and distribution pathways of the Himalayan Balsam (I. glandulifera, syn. I. roylei), one of the well-known alien invasive plants in the Czech Republic (Central Europe). We also explain the mechanisms behind the successful spread of the species and sketch its future development., and Hana Skálová, Jan Čuda.