Short-term effects of airborne ragweed pollen on clinical symptoms of hay fever in a panel of 30 patients

Citation: Caillaud, D., Thibaudon, M., Martin, S., Ségala, C., Besancenot, J.P., Clot, B., François, H. (2014) Short-term effects of airborne ragweed pollen on clinical symptoms of hay fever in a panel of 30 patients. Journal of Investigational Allergology and Clinical Immunology, 24 (4): 249 – 256 .

Abstract: Objectives: Ragweed, Ambrosia artemisiifolia, is a highly allergenic annual herbaceous plant that is spreading quickly across the globe. Few studies have investigated the relationship between ragweed pollen counts and hay fever symptoms. We investigate the dose-response relationship between ragweed exposure in patients sensitized to ragweed and daily hay fever symptoms. Method: A panel study was conducted among 31 adult patients sensitized to A artemisiifolia in France and Switzerland. Rhinitis, conjunctivitis, and bronchial symptoms were recorded daily, as well as daily pollen counts of ragweed, air pollutants, and meteorological data over 2 successive years. Data were analyzed with generalized estimating equation models to quantify effects of ragweed pollen whilst controlling for confounders. Results: The relationship between ragweed pollen and the percentage of patients with nasal, ocular, and bronchial symptoms was linear. For every increase of 10 grains/m3, the odds ratio (OR) (95% confidence interval) for nasal symptoms was, in 2009, 1.18 [1.04-1.35] on weekdays and 1.43 [1.16-1.75] at weekends, and in 2010, 1.04 [1.00-1.07] on weekdays and 1.25 [1.06-1.46] at weekends. The OR for ocular symptoms was 1.32 [1.16-1.56] in 2009 and 1.05 [1.02-1.07] in 2010. Finally, the OR for bronchial symptoms was 1.14 [1.03- 1.25] in 2009 and 1.03 [0.97-1.08] in 2010. Conclusion: There is a statistically significant linear relationship between ragweed pollen counts and hay fever symptoms. Our study shows that nasal symptoms differ on weekdays and at weekends.

Areas of high conservation value in Georgia: present and future threats by invasive alien plants

Citation: Thalmann, D J K, Kikodze, D, Khutsishvili, M, Kharazishvili, D, Guisan, A, Broennimann, O, Müller-Schärer, H (2014) Areas of high conservation value in Georgia: present and future threats by invasive alien plants. Biological Invasions, In Press. DOI:10.1007/s10530-014-0774-2

Springer Link

Abstract: Georgia is known for its extraordinary rich biodiversity of plants, which may now be threatened due to the spread of invasive alien plants (IAP). We aimed to identify (1) the most prominent IAP out of 9 selected potentially invasive and harmful IAP by predicting their distribution under current and future climate conditions in Georgia as well as in its 43 Protected Areas, as a proxy for areas of high conservation value and (2) the Protected Areas most at risk due to these IAP. We used species distribution models based on 6 climate variables and then filtered the obtained distributions based on maps of soil and vegetation types, and on recorded occurrences, resulting into the predicted ecological distribution of the 9 IAP’sat a resolution of 1 km2. Our habitat suitability analysis showed that Ambrosia artemisiifolia, (24 and 40 %) Robinia pseudoacaia (14 and 19 %) and Ailanthus altissima (9 and 11 %) have the largest potential distribution (predicted % area covered), with A. altissima the potentially most increasing one over the next 50 years (from 9 to 13 % and from 11 to 25 %), for Georgia and the Protected Areas, respectively. Furthermore, our results indicate two areas in Georgia that are under specifically high threat, i.e. the area around Tbilisi and an area in the western part of Georgia (Adjara), both at lower altitudes. Our procedure to identify areas of high conservation value most at risk by IAP has been applied for the first time. It will help national authorities in prioritizing their measures to protect Georgia’s outstanding biodiversity from the negative impact of IAP.

Practical and economic efficacy of Ambrosia artemisiifolia L. surveillance in compliance with the international standards

Citation: Podberezko, I.M., Pylypenko, L.A., Mar’uschkina, V.Y., Borzykh, O.I. (2013) Practical and economic efficacy of Ambrosia artemisiifolia L. surveillance in compliance with the international standards. Journal of Plant Protection Research, 53( 4 ): 392 – 398

Abstract: Ambrosia artemisiifolia distribution in the Ukraine for the 1973–2013 period was analyzed. The infested areas were consequently grouped into 6 categories. Intense infestation in the region was the reason for the analysis and the categorization. A practical approach to the A. artemisiifolia surveillance system which complied with the International Standards for Phytosanitary Measures concerning “a pest free area”, “pest free places of production”, “pest free production sites” and “an area of low pest prevalence” was recommended. This action should drive the policy-making process to underpin national legislation regarding invasive species. The opportunity also presents itself for improved communications with growers and stakeholders because of the more transparent and cost effective system of A. artemisiifolia surveillance offered. There would be a chance to slow down the A. artemisiifolia invasion even though this invasive species has already occupied 3.6 million hectares.

Potential distribution of two Ambrosia species in China under projected climate change

Citation: Qin, Z., DiTommaso, A., Wu, R. S. and Huang, H. Y. (2014). Potential distribution of two Ambrosia species in China under projected climate change. Weed Research DOI: 10.1111/wre.12100.

Link to Wiley Online Library

Abstract: The invasion of Ambrosia artemisiifolia and Ambrosia trifida from their native range to occupy large areas in China has raised considerable concern. Using the maximum entropy (Maxent) method, we developed models for each Ambrosia species, based on occurrence records from both native ranges (North America) and their invaded ranges (e.g. northern and south-western Europe) to predict the availability and distribution of suitable habitats for these two species in China. For each species, we also assessed potential shifts in habitat suitability for the year 2050, using three general circulation models (GCMs) and two emission scenarios. Elevation and average mean precipitation in October contributed most to model development for both species. Potential distribution projections under future climatic change scenarios suggested an averaged percentage of suitable area (2.21%) and habitat gain (1.49%) in A. artemisiifolia distribution, with further expansion to environmentally favourable locations in south-east coastal regions, northern Taiwan and the Beijing–Tianjin–Tangshan area in northern China. Future predicted percentage of suitable area for A. trifida was 0.03% with a very limited suitable habitat gain of <1% although this species had the potential to continue to spread in northern China. Our findings suggest that management priorities should be focused on A. artemisiifolia, whilst effective control strategies for A. trifida may be optimised by concentrating efforts on those relatively fewer regions of China where the species is currently abundant.

Task Force Population Dynamics kicks off with workshop ragweed demography

Twenty participants, from France to Armenia, gathered Friday 23 May in Montpellier for the first meeting of the Task Force Population Dynamics. In a half-day workshop, organised by the coordinator Suzanne Lommen (CH), and the local organiser Bruno Chauvel (FR), everyone was trained to conduct the protocol, especially developed to study the demography of common ragweed.

Finding the Ambrosia plants

Finding the Ambrosia plants

The participants received the protocol, standardized record forms and help tools. After a presentation, they went outside to practice all aspects of the protocol on an artificially created population in the garden – from setting up the study plots, tagging individual plants, to measuring the viability of seeds extracted from soil samples. In the final discussion, the methods to take measures were optimized and fine-tuned. Now everyone is prepared to monitor their local ragweed populations. An online forum was initiated to share experiences during the field season.

Delimiting plots and measuring plants

Delimiting plots and measuring plants

Sampling soil, extracting and identifying Ambrosia seeds, and analysing their viability

Sampling soil, extracting and identifying Ambrosia seeds, and analysing their viability