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New evidence shows impact of air pollution on natural vegetation and crops

While there is increasing awareness about the health effects of air pollution, its impact on ecosystems and crops is sometimes overlooked. Recent air pollution peaks in Warsaw, Krakow and other cities in Poland and other parts of Europe also have significant effects on plant life. This, in turn, impacts on agricultural yields and food production and can lead to significant economic losses.

An international group of scientists held their annual meeting, hosted by the Poznan University of Life Sciences and the Institute of Botany, in Poznan, Poland, from 14 to 17 February 2017, to review new evidence of the impacts of certain air pollutants on vegetation and discuss the consequences for biodiversity. The meeting was attended by some 100 experts from 25 countries. The group of scientists, known as the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation), established within the framework of the UNECE Convention on Long-range Transboundary Air Pollution, has worked to improve the understanding of the impacts of air pollution on crops and other vegetation for the past 30 years. ICP Vegetation is led by the Centre for Ecology & Hydrology in the United Kingdom.

Impact on food production and economic consequences

Some crops have been found to be particularly sensitive to certain types of air pollution. Ground-level ozone — formed when emissions from cars (e.g., nitrogen oxides) react with other pollutants in sunlight — affects plant growth and is estimated to cause relative global crop losses for staple foods like soy (6%-16%), wheat (7%-12%) and maize (3%-5%). At the European level, studies have estimated that the economic losses owing to the impact of ozone on 23 crops amounted to €6.7 billion, with global losses estimated at up to US$ 26 billion. Scientists at the meeting in Poznan considered new critical ozone levels for sensitive plant species to quantify the risks to vegetation posed by ozone pollution.

Mosses as monitors of pollution

Since 1990, naturally growing mosses have been sampled every five years in the framework of ICP Vegetation. Mosses are used as so-called biomonitors of atmospheric deposition of pollutants, such as heavy metals and nitrogen, to assess spatial pollution concentration patterns and temporal trends across Europe and beyond. Mosses thus provide a good indication of areas at risk from high pollutant deposition. Participants at the meeting discussed progress within the 2015/16 moss monitoring survey, welcomed the contributions of many scientists from countries in Eastern Europe, the Caucasus and Central Asia and encouraged further contributions from countries in Asia, Africa and South America in ICP Vegetation’s work.