One in five plant species at risk, hitting food security and crop choices

In the State of the World's Plants report, scientists warn than crops such as bananas, kidney beans, and sweetcorn are at risk of extinction due to disease, habitat changes and farming practices. It highlights the threat not only to food security but also to medicine supplies, adding that of the world’s known 390,000 species of plant, over 30,000 are used by people. Furthermore, over 5,000 invasive species cause billions of dollars’ worth of damage every year. The scientists predict that by 2100 a third of the land used to grow bananas and maize in Africa and two-thirds of the land used for beans will be unusable. Crops such as these are expected to be replaced by more hardy crops, such as root vegetables and, in particular, drought-tolerant grain such as millets, which we highlighted last year. Many are starting to take note of millets given that they are robust dryland crops that can be grown relatively easily from seed in higher temperatures and skeletal soils without the need for synthetic fertilisers. A US study of 66 common crops found that focus on high-yielding varieties led the number of ancient varieties to shrink by 93% in the first 80 years of the 20th century. As we noted last year, bananas are also at risk of extinction due to the global spread of Panama disease, and coffee is at risk due to increased drought conditions.

Bananas, sweetcorn and kidney beans all risk being in shorter supply because of the impact of climate change and intensive farming, scientists have warned.

Up to a third of the land used to grow bananas and maize in Africa and two-thirds of land for beans will be ‘unviable’ by the year 2100, they claim.

As early as 2025, these crops will need to be replaced by tougher root vegetables such as yams and drought-resistant grains such as millet.

Bananas, sweetcorn, kidney beans and coffee beans all risk being in shorter supply because of the impact of climate change and intensive farming

Coffee production is also likely to be ‘drastically affected’, a report published by the Royal Botanic Gardens, Kew, says.

The State of the World’s Plants report was compiled by 80 scientists to give the first global insight into issues affecting plants today.

It revealed that more than one in five of the 391,000 known plant species were threatened with extinction, mainly from disease, habitat destruction, climate change or poor farming practices.

Many species would be ‘on borrowed time’ by 2050, it said, and plants would either become extinct, migrate to different habitats or be forced to alter their properties to adapt to rising temperatures and changing rainfall patterns.

Some plants were already in ‘extinction debt’ – where they had been hit by global warming but the impact was not yet known, the report suggested.

Research by the International Center for Tropical Agriculture modelled how nine common crops from sub-Saharan Africa would fare over the coming decades and warned some would need to be replaced with hardier roots and grains to maintain food supplies.

Professor Kathy Willis, of the Royal Botanic Gardens, said yesterday: ‘Having proof that root crops like cassava and yams are among the climate-smart crops of the future for sub-Saharan Africa is vital for informing policy and planning today.’

Coffee production in Ethiopia was also highly likely to be hit by climate change, another study in the report showed, but this could be counteracted with new areas for plantations.

About 2,000 species of plants are discovered every year.

Last year alone, new finds included an insect-eating sundew found through Facebook, five types of onion and a close relative of the sweet potato.

Invasive plants such as Japanese knotweed and cheatgrass were a global problem with nearly 5,000 species identified.

These alien plants cost the UK £1.7 billion a year.

Modern farming tends to prioritise species with the highest yield which has led to a dramatic reduction in the number of ancient varieties of fruits, vegetables and cereals in existence.

A US study of 66 common crops found the number of varieties shrank by 93 per cent in the first 80 years of the 20th century.

About 40 per cent of sub-Saharan Africa’s food exports go to the EU, mainly to Britain and France.