Pollution causing malnutrition in trees

LONDON: Pollution is changing the fungi that provide mineral nutrients to tree roots, causing plants in Europe to become malnutritioned, a study has found.


To get nutrients from the soil, trees host fungi, known as mycorrhizal fungi, in their roots. These fungi receive carbon from the tree in exchange for essential nutrients, like nitrogen, phosphorus and potassium, which they gather from the soil.


This plant-fungal symbiotic relationship is crucial for the health of the tree. Recent studies have noted signs of tree malnutrition across Europe, such as

discoloured leaves or leaves lost from the crown.

A ten-year study led by Imperial College London (ICL) and the Royal Botanic Gardens in the UK showed that tree characteristics and local air and soil quality have a large impact on mycorrhizae. The study, published in ‘Nature’, examined 40,000 roots from 13,000 soil samples at 137 forest sites in 20 European countries. This allowed researchers to discover large-scale trends in mycorrhizal communities, including their tolerance to pollution.

“There is a trend of tree malnutrition across Europe, which leaves forests vulnerable to pests, disease and climate change,” said lead researcher Martin Bidartondo, from ICL.

“The study found that European pollution limits may be far too high,” said Bidartondo.

“In North America the limits are much lower. Our trees in Europe are not more tolerant than those that are in North America — their fungi are just suffering more,” he added.