Studies in the past have indicated that the knock-on effects of climate change and global warming have a significant impact on plant growth and plant phenology. But a recent study has revealed that even cactus plants – some species of which are tolerant to extreme heat – could be threatened with extinction due to climate change.
According to a team of researchers in the UK and US, 60 percent of cactus species will end up in less hospitable climates over the coming decades as global warming sets in. These new findings – published recently in the journal Nature Plants – challenge the long-held assumption that these iconic desert plants will thrive with more heat.
By 2070, up to 90 percent could be threatened with extinction due to climate change, habitat loss and other stressors, triple the current percentage, scientists reported in the new study titled “Elevated extinction risk of cacti under climate change”.
Some 1,500 species of cacti spread across the Americas live in varying climes, ranging from sea-level deserts to the high Andes mountains, from bone-dry ecosystems to humid tropical forests, an AFP report on the study adds. Biodiversity hotspots rich in species and numbers include central Mexico and the Brazilian Atlantic Forest, the report explains.
To test the notion that cacti will benefit from a warmer and more drought-prone world, researchers led by Michiel Pillet from the University of Arizona examined data on more than 400 species and ran climate models projecting how they would fare at mid-century and beyond under different greenhouse gas emissions scenarios.
The findings “paint a more pessimistic future,” according to the study. “Overall, the number of cactus species at risk is projected to increase sharply in the future, especially in current richness hotspots,” researchers said in the study’s abstract. Currently, the main threat to cacti is expanding agriculture, along with land degradation, biodiversity loss and harvesting for various uses, the AFP report explains.
Even without climate change, cacti "is one of the most endangered groups of organisms on the planet," with more than 30 percent classified as at risk of extinction, the authors of the study noted. Under a moderate emissions scenario in line with current policies, global warming will soon be a significant threat as well.
"Our results suggest that climate change will become a primary driver of cactus extinction risk, with 60 to 90 percent of species assessed negatively impacted" by global warming, the researchers reported. Within four or five decades, some 25 percent of cacti species could experience unfamiliar climates over a quarter of their current range.
Studies in the past have also shown impaired photosynthesis with only two degrees Celsius of global warming. Further research – as per a December 2021 study from the University of California - Santa Cruz – has shown that some plant species are struggling to keep pace with climate change in human-dominated landscapes, with changes in plant phenology lagging behind rising temperatures across a majority of the Northern Hemisphere.
That’s not all. Warmer winters – due to the effect of rising temperatures around the world – are also helping pathogens, pests and invasive species that pose a significant threat to vegetation. According to a June 2021 study backed by the United Nations’ Food and Agriculture Organization, climate change is making plant pests which ravage important agricultural crops even more destructive. This scientific review looked at 15 plant pests – such as the fall armyworm and desert locusts – that have spread or may spread due to climate change.