A significant proportion of the world's cactus species are under threat of extinction due to human activities, according to a global study.
The study, published Tuesday in the journal Nature Plants, found 31 per cent of cactus species are at risk.
Collecting live plants and seeds for trade or private collections, as well as livestock ranching and other farming practices in areas where prickly plants grow were cited as two main threats.
This makes cacti the fifth most threatened major group of organisms, after amphibians, coral reefs, coniferous trees, and other types of plants, according to the study.
Nearly all of the world's cactus species grow in the Americas, with only one growing in Africa and Asia.
The lead author of the study, Barbara Goettsch, told The Guardian the assessment's results "came as a shock."
“We did not expect cacti to be so highly threatened and for illegal trade to be such an important driver of their decline,” she said.
International Union for Conservation of Nature director general Inger Andersen echoed Goettsch's surprise, telling Reuters the findings were disturbing.
"They confirm that the scale of the illegal wildlife trade, including trade in plants, is much greater than we had previously thought," she said.
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