In: American Journal of Botany, 2013, vol. 100, no. 8, p. 1555–1561
Premise of the study: Because seeds have essential functions in the life cycle of plants, even subtle changes in their characteristics may have important demographic consequences. In this study, we examined whether potential changes in seed characteristics as a result of polyploidy or postintroduction evolution may have contributed to the invasion of Centaurea stoebe (Asteraceae). This plant...
|
In: Journal of Biogeography, 2013///n/a–n/a
Aim: The spotted knapweed (Centaurea stoebe), a plant native to south-east and central Europe, is highly invasive in North America. We investigated the spatio-temporal climatic niche dynamics of the spotted knapweed in North America along two putative eastern and western invasion routes. We then considered the patterns observed in the light of historical, ecological and evolutionary...
|
In: Weed Technology, 2013, vol. 27, no. 2, p. 405–411
This study determined the potential of the tortoise beetle (Coleoptera: Chrysomelidae) to control Canada thistle (Asteraceae) in Iran. Genetic analysis of the tortoise beetle, based on mitochondrial DNA, confirmed the presence of the species in Iran. A field experiment using five insect densities (0 to 20 larvae plant−1) showed a positive correlation between the number of larvae transferred and...
|
In: Journal of Ecology, 2013, p. -
Biogeographic experiments that test how multiple interacting factors influence exotic plant abundance in their home and recipient communities are remarkably rare. We examined the effects of soil fungi, disturbance and propagule pressure on seed germination, seedling recruitment and adult plant establishment of the invasive Centaurea stoebe in its native European and non-native North American...
|
In: Ecology, 2013, p. -
Knowledge from basic plant ecology suggests that impact of one plant species on another is driven by either competition for the same limiting resources, or by unique plant traits. These processes might be context specific, explaining a differential impact of exotic plant invaders in the native vs. introduced range. With the help of a conceptual framework, we aimed at identifying the relationship...
|
In: Ecology, 2013, vol. 94, no. 5, p. 1005–1014
The evolution of optimal life history strategies is central for the fitness of organisms in a given environment. Besides divergent selection, other factors may determine regional patterns of differentiation and contribute to life history evolution. In a common-garden environment over three years, we examined life history differentiation across different eco-geographical regions and effects of a...
|
In: Weed Research, 2013, p. -
Centaurea stoebe is native to Europe and Western Asia and was introduced into North America in the late 19th century, where it has become highly invasive. In its native range, C. stoebe occurs in two cytotypes, namely diploids (2n = 18) and tetraploids (2n = 36), but only the tetraploid form has been identified in the invaded range. We used special growth pouches to determine whether diploid and...
|
In: PLoS ONE, 2012, vol. 7, no. 11, p. e50284
Phenotypic plasticity may allow organisms to cope with altered environmental conditions as e.g. after the introduction into a new range. In particular polyploid organisms, containing more than two sets of chromosomes, may show high levels of plasticity, which could in turn increase their environmental tolerance and invasiveness. Here, we studied the role of phenotypic plasticity in the invasion...
|
In: Mycorrhiza, 2012, p. -
Soil nutrient availability and colonization by arbuscular mycorrhizal fungi are important and potentially interacting factors shaping vegetation composition and succession. We investigated the effect of carbon (C) addition, aimed at reducing soil nutrient availability, on arbuscular mycorrhizal colonization. Seedlings of 27 plant species with different sets of life-history traits (functional...
|
In: Annals of Botany, 2012, p. -
Background and Aims: In a mixed-ploidy population, strong frequency-dependent mating will lead to the elimination of the less common cytotype, unless prezygotic barriers enhance assortative mating. However, such barriers favouring cytotype coexistence have only rarely been explored. Here, an assessment is made of the mechanisms involved in formation of mixed-ploidy populations and coexistence...
|
