« Back

International study warns that global warming may increase soil-borne plant pathogens

International study warns that global warming may increase soil-borne plant pathogens

University of Alicante distinguished researcher Fernando T. Maestre collaborates in this work published in the prestigious journal Nature Climate Change

An international study published in the prestigious journal Nature Climate Change warns that global warming will increase the proportion of soil-borne plant pathogens worldwide. Just one teaspoon of soil contains millions of microbes. Most of these soil organisms are beneficial to humankind by regulating our climate, supporting the fertility of our soils, and helping us produce food and fibre. Others, however, are capable of devastating entire crops resulting in important economic losses, and even human starvation.

This new study, conducted by researchers from Spain, Australia, Germany and China, provides experimental and global observational evidence that the proportion of soil-borne plant pathogens will increase in a warmer world. Many of the most aggressive plant pathogens, like Alternaria alternata or Fusarium oxysporum, are soil-borne fungi Understanding the ecology and future changes in the abundance of these pathogens is critical to better understand how climate change will impact food production and human livelihoods worldwide.

First atlas of soil-borne plant-pathogenic fungi

The work provides the world's first atlas of soil-borne plant-pathogenic fungi and highlights the places on Earth where these organisms are more common today and in the upcoming 30 years. It also indicates that soils are critical reservoirs of some of the most important plant pathogens worldwide. "Here, we provide solid evidence that experimental warming and global air temperatures are positively associated with higher proportions of soil-borne pathogens in soils worldwide", notes Manuel Delgado-Baquerizo from Pablo de Olavide University, lead author of the paper.

The researchers used DNA sequencing to investigate the association between the proportion of soil-borne pathogens and increases in temperature across different types of soil. 

The new study highlights that large regions of Earth from Asia, Africa, Australia and America contain high proportions of soil-borne plant pathogens. These regions correspond to warm climates such as those from hot deserts and tropical forests. "Our global maps identified the hotspots for soil-borne fungal plant pathogen today, and warn us about an overall global increase in the proportion of these important pathogens with global warming" says Delgado-Baquerizo. According to University of Alicante head of the Dryland Ecology and Global Change Laboratory and co-author of the study, the ongoing global pandemic reminds us about the impact that microorganisms can have on our societies and economies, and about the importance of learning more about their ecology. He added that by providing novel maps about the current and future distribution of important plant pathogens our results can guide management actions to avoid future food crisis associated to climate change.

Field research

To conduct the study, the researchers collected soil samples from 235 different locations across six continents and 18 countries, spanning an entire range of climates from deserts to tropical forests. These samples include those gathered from the global dryland survey led by the University of Alicante researcher within the framework of his BIOCOM project, funded by the European Research Council (ERC).

The findings of this global study have been validated using data from a field climate change experiment that Fernando T. Maestre and his research group have been maintaining for the last decade thanks to the support of the ERC-funded BIOCOM and BIODESERT projects. This experiment mimics the climate forecasted for the second half of the 21st century, and is one of the very few long-term climate change experiments being maintained in the world´s drylands for more than 10 years. This study highlights the relevance of conducting large-scale sampling and long-term experiments, something that would not have been possible without the support of the ERC, which has funded the Dryland Ecology and Global Change Laboratory all these years, as stated by the distinguished researcher from the University of Alicante.

Reference: "The proportion of soil-borne pathogens increases with warming at the global scale". Nature Climate Change, 2020 doi: 10.1038/s41558-020-0759-3