Citation: Leiblein-Wild, M. C., Kaviani, R., Tackenberg, O. (2014) Germination and seedling frost tolerance differ between the native and invasive range in common ragweed. Oecologia , 174 (3): 739 – 750
Springer Link Open Access
Abstract: Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. The characterization of differences between populations in native and invasive ranges may improve our understanding of range expansion and adaptation. Here, we investigated germination characteristics of Ambrosia artemisiifolia L., a successful invader in Europe, under a temperature gradient between 5 and 25 °C.
Citation: Martin, M. D., Zimmer, E. A., Olsen, M. T., Foote, A. D., Gilbert, M. T. P. and Brush, G. S. (2014), Herbarium specimens reveal a historical shift in phylogeographic structure of common ragweed during native range disturbance. Molecular Ecology. doi: 10.1111/mec.12675
Wiley Online Library
Abstract: Towards a direct comparison of genetic structure now and during intense anthropogenic disturbance of the late 19th century, we sampled 45 natural populations of common ragweed across its native range as well as historical herbarium specimens collected up to 140 years ago. Bayesian clustering analyses of 453 modern and 473 historical samples genotyped at three chloroplast spacer regions and six nuclear microsatellite loci reveal that historical ragweed’s spatial genetic structure mirrors both the palaeo-record of Ambrosia pollen deposition and the historical pattern of agricultural density across the landscape. Furthermore, for unknown reasons, this spatial genetic pattern has changed substantially in the intervening years. Following on previous work relating morphology and genetic expression between plants collected from eastern North America and Western Europe, we speculate that the cluster associated with humans’ rapid transformation of the landscape is a likely source of these aggressive invasive populations.
More information on the next big SMARTER meeting, 23-25 May 2014, in Montpellier, France, here: http://ragweed.eu/201405-smarter-wg-and-core-group-meetings/
Dutch scientists and stakeholders discussed how to involve citizen scientists and patients in Ambrosia research. In the winter of 2013, representatives of SMARTER met in the Netherlands with local experts on Ambrosia management, allergenic pollen, and communication to discuss how to involve laymen in SMARTER scientific research on ragweed.
- Floron (the Dutch organisation for public involvement in vegetation research in the Netherlands) sees potential in involving volunteers in the SMARTER Ambrosia survey (both recording distribution and monitoring populations). A recruitment campaign was designed. Download the flyer of the campaign here.
- A team of Dutch professionals will think about the distribution of the SMARTER Ambrosia Reporter App. A stakeholder meeting will be organised in the ragweed season.
- The participants found a common interest to establish collaborations, by linking data from ragweed distribution, pollen stations, and patients diaries on hayfever symptoms, and medical reports from hospitals.
Citation: Milakovic I, Fiedler K, and Karrer G (2014) Management of roadside populations of invasive Ambrosia artemisiifolia by mowing. Weed Research, DOI: 10.1111/wre.12074
Wiley Online Library Open Access
Abstract: Ambrosia artemisiifolia (common ragweed) is a highly allergenic alien weed in Europe, which spreads rapidly along roadsides. Road verges are subject to frequent mowing, which further increases the spreading of the plants’ seeds. Ambrosia artemisiifolia reacts to cutting by producing new shoots, which are able to develop flowers and ultimately new seeds. An effective mowing regime that would decrease the production of seeds and their dispersal is desirable to control the spread of the plant, but an appropriate way of mowing has yet to be found. In this study, we explored how the reproductive traits of A. artemisiifolia plants in seven spontaneous roadside populations reacted to the application of different mowing regimes over 3 years. The mowing regimes that were applied differed in the timing and frequency of cuttings. We found that the cutting regime, if appropriately timed, can strongly influence the production of male inflorescences (i.e. allergenic pollen), of female flowers (i.e. seeds) and had an impact on the phenological development of the plant. Based on our findings, we suggest that the optimal management of the plant along roadsides must be adjusted to its phenological development. The most effective mowing method of control consists of a first cut shortly before male flowering, to limit the quantities of released pollen, followed by subsequent cuts before the onset of new flowers on the resprouting lateral shoots.
The authors acknowledge COST SMARTER for financing the Open Access publication of this paper in Weed Research