Impacts of Climate change and seed dispersal on airborne ragweed pollen concentrations in Europe

Common ragweed (Ambrosia artemisiifolia) is an invasive weed native to North America producing very allergenic pollen which causes serious health effects like rhinitis, asthma and atopic dermatitis. It was introduced in Europe since the mid-19th century and invaded large areas during the last few decades (Pannonian plain, Northern Italy and South-Eastern France). Furthermore, there is a high potential for ragweed spread in current suitable habitats and future changes in Climate and land use may increase the spread by altering the climatic niche determined by physiological thresholds or affecting cropping patterns. The rate of spread depends also on seed dispersal due to natural or anthropogenic processes and the efficiency of ragweed eradication policies. However, ragweed airborne pollen concentrations depend not only on plant infestation, but also on phenology, pollen production, release, dispersion and atmospheric transport. Here, we present the first integrated modelling framework, based on an explicit representation of plant phenology, pollen production, and release to the atmosphere, to assess future changes in airborne pollen concentration under scenarios of climate and land use changes and seed dispersal. Two model suites are implemented differing in the atmospheric processing and in the driving climate models. The CHIMERE suite uses the Chemistry- Transport Model CHIMERE model, forced by regional climate simulations from the WRF model downscaling of the IPSL-CM5A-MR model. The RegCM suite uses the RegCM4 regional climate model forced by global climate simulations from HadGEM CMIP5. We performed three types of simulations (50 km grid covering Europe), which are hind-cast (2000–2012), historical (1986–2005) and future (2041–2060) simulations. The hindcast simulations, forced by ERAInterim reanalysis, are performed to calibrate and evaluate the modelling chain. The historical simulations are carried out using calibrated ragweed density to serve as a reference simulation for the future. We considered two contrasting RCPs (Representative Concentration Pathways) climate change scenarios including a high-end (RCP 8.5) and moderate (RCP 4.5) climate change scenarios and three seed dispersal scenarios (reference, slow and rapid). We show that airborne pollen concentrations may drastically increase in 2050 by a factor of 4.5 under highend (RCP 8.5) and 4.0 under moderate (RCP 4.5) climate change scenarios. This upsurge is largely dependent on the seed dispersal rate, making this increase vary in a range of factors from 2 to 12 according to the range of formulated assumptions. We estimate that about one third of the projected increases of pollen concentration are due to the on-going seed dispersal within the present niche regardless of climate change. Climate change will be responsible of two thirds of the future pollen loads increase. It will extend the habitat suitability for ragweed in Northern and Eastern Europe and result in higher pollen concentrations in established ragweed areas mostly due to a larger primary production with increasing CO2. Therefore, future increase of airborne pollen concentrations will be caused by the combined effects of climate change and ragweed seed dispersal in current and future suitable areas. Our results indicate that controlling the current European ragweed invasion will become more difficult in the future as the environment will be more favourable for ragweed growth and spread, highlighting the need for the development of effective and regionally co-ordinated eradication programmes

Unaccounted variability in NH3 agricultutral sources detected by IASI contributing to European spring haze episode

info:eu-repo/semantics/nonPublishe

Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe

Common ragweed (Ambrosia artemisiifolia) is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals1. Ragweed plants could further invade European land with climate and land-use changes2,3. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by 2050 airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy

Establishing a Diagnosis: Inventorying, Monitoring and Assessing

International audienceImproving air quality is a major challenge for public health and the environment. Assessing the contribution of agricultural activity to air pollution and the resulting impacts is a prerequisite for recommending mitigation practices. More important, their long-term adoption can only be justified by performing a real-time assessment of their effectiveness. Since the 1990s, using emission indicators, air contamination levels and environmental impacts has indeed become a widespread means of supporting decision-making at different levels, risk management and public policy assessment. However, this assessment is made difficult owing to the complex network of processes involved and the variability in pollutant emission and deposition. This chapter first details the methodologies implemented for emission inventories, used to better target the largest contributing sources, to check whether national commitments have been met, and to assess the trends. It also presents observation networks established to monitor background air pollution, deposition as precipitation, gases and particles in rural and forest areas, and impacts on terrestrial ecosystems. Finally, it outlines the indicators used to assess the impacts of agricultural practices on human and ecosystem health via the atmospheric compartment and it gives examples of their practical use to manage pollution risks, evaluate agricultural practices or compare agricultural products

Source Regions of Ragweed Pollen Arriving in South – Western Poland and the Influence of Meteorological Data on the HYSPLIT Model Results

We have investigated the relationship between the inflow of air masses and the ragweed pollen concentration in SW Poland (Wrocław) for a 10-year period of 2005-2014. The HYSPLIT trajectory model was used to verify if episodes of high concentrations can be related to regions outside of the main known ragweed centres in Europe, like Pannonian Plain, northern Italy and Ukraine. Furthermore, we used two different meteorological data sets (the global GDAS data set and from the WRF mesoscale model; the meteorological parameters were: U and V wind components, temperature and relative humidity) into HYSPLIT to evaluate the influence of meteorological input on calculated trajectories for high concentration ragweed episodes. The results show that the episodes of high pollen concentration (above 20 pm-3) represent a great part of total recorded ragweed pollen in Wrocław, but occur rarely and not in all years. High pollen episodes are connected with air masses coming from south and south-west Europe, which confirms the existence of expected ragweed centres but showed that other centres near Wrocław are not present. The HYSPLIT simulations with two different meteorological inputs indicated that footprint studies on ragweed benefit from a higher resolution meteorological data sets

Modelling Exchanges: From the Process Scale to the Regional Scale

International audienceThis chapter shows how the knowledge on the processes of surface exchange and atmospheric fate of different pollutants from agriculture or with an impact on agroecosystems is factored into mathematical simulation tools. It also considers the complexity of the interactions involved, the quantities of matter exchanged between agroecosystems and the atmosphere, and the measurement methods used to quantify them. The resulting models, which range from highly local (plant, leaf …) to global scales, ultimately enable to assess the impacts of changes in agricultural practices or climate change on pollutant exchanges between the atmosphere and agroecosystems. We describe different modelling approaches at the process, field, landscape and regional scales with different integrative levels. Model results are useful to understand how different processes interact and to predict how different environmental conditions, future climate or agricultural practices affect air quality. Models can also help identify levers for emission mitigation and estimate their efficiency