If we add other factors (disappearance of habitats, degradation of the natural environment, etc.), up to 90% of cacti could be threatened with extinction by 2070, three times the current estimate. , believe the researchers in this study published Thursday in Nature Plants.
Some 1,500 cactus species spread across the Americas live in different climates, ranging from sea-level deserts to the high mountains of the Andes, from arid ecosystems to tropical rainforests.
Species-rich biodiversity hotspots include central Mexico and the Atlantic Forest along the coast of Brazil.
To test the hypothesis that cacti would benefit from a warmer, more drought-prone world, the researchers, led by Michiel Pillet of the University of Arizona, examined data on more than 400 species, and used models to forecast their evolution at the mid-century horizon and beyond, according to different scenarios of greenhouse gas emissions.
portray a more pessimistic futureaccording to the study.
Currently, cacti are mainly threatened by the expansion of agriculture, the degradation of the natural environment, the loss of biodiversity and their harvesting for various purposes.
Even without climate change, cacti
are one of the most endangered groups of organisms on the planetwith more than 30% of them listed as threatened with extinction, the authors note.
And global warming will soon become a threat too, if emissions are not drastically reduced.
” Our results suggest that climate change will become a major driver of cactus extinction risk, with 60-90% of assessed species negatively affected. »
By 2070, around 25% of cactus species could experience an unknown climate across a quarter of their current range.
Previous studies have shown that photosynthesis – the process by which plants use sunlight to grow from CO2 and water – was compromised by global warming.