Invasive ragweed is spreading rapidly through Europe. Modelling by EU scientists, including a team a Rothamsted Research, suggests that the plant's spread may continue northwards with climate change.   

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EU scientists tasked with looking into the potential spread of ragweed developed a computer model to predict shifts in distribution of ragweed. They found it could spread northwards in response to climate change.

Dr Jonathan Storkey, who led the investigations at Rothamsted Research in Hertfordshire, said, "The spread of ragweed is an ongoing invasion event and our results suggest that the species is yet to fill the available climatic niche space under current conditions. For example the climate in the south of the UK is predicted to be suitable for ragweed populations to persist. However, the spread and establishment of the species in new areas relies on appropriate land use, specifically the cultivation of crops such as maize and sunflower, therefore, opportunities for it to spread into new areas may currently be limited by management factors as opposed to climatic tolerances."

"Anticipating future spread in response to changes in climate or land use will, therefore, be important for mitigating potential impacts on human health and crop production," Dr Storkey added.

Making predictions, the researchers said that, although it has clear potential to spread northwards, further southward spread of ragweed looks less likely, due to limited water availability.

The researchers recommended further surveillance and study of existing ragweed patches in the UK, in a bid to prevent it from becoming a serious problem. However, they added that, ultimately, "[ragweed's] impacts in the future in the UK will be determined by cropping patterns and the level of control."