- Cacti are the fifth most threatened group of species in the world, according to the first-ever global assessment of cacti.
- Theft and illegal trade for the horticulture industry and private collections are the major drivers of extinction, affecting 47 percent of the threatened cacti species, experts found.
- Cacti habitats — typically arid areas — are often overlooked in conservation planning, the authors write.
Cacti are the fifth most threatened group of species in the world, according to the first-ever global assessment of this plant group by the International Union for the Conservation of Nature (IUCN).
Thirty-one percent of all cactus species are threatened with extinction — in contrast to 25 percent mammals and 13 percent birds — the report published today in Nature Plants found.
Theft and illegal trade for the horticulture industry and private collections emerged as the major drivers of extinction, affecting 47 percent of the threatened cacti species.
“These findings are disturbing,” Inger Andersen, IUCN Director General, said in a statement. “They confirm that the scale of the illegal wildlife trade — including trade in plants — is much greater than we had previously thought, and that wildlife trafficking concerns many more species than the charismatic rhinos and elephants which tend to receive global attention.”
Cacti are among the most sought after groups of plants. Their “unique appearance, unpredictably beautiful flowers and rarity in terms of the narrowness of their geographic range,” make them especially attractive to collectors, the authors write. This demand drives both their national and international illegal trade. In fact, around 86 percent of the threatened cacti used in horticulture are extracted from wild populations, the assessment revealed.
For example, illegal collection of the golf ball cactus (Mammillaria herrerae) — a whitish golf-ball-like cactus species with beautiful pink flowers — has reduced its populations by over 95 percent in the last 20 years.
Since 1975, when the cacti family was included in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), illegal trade has reduced to a certain extent, the authors write. Moreover, the availability of cacti grown from seed in international markets has helped reduce unscrupulous collections, they add.
“However, the threat of collection prevails, especially in those countries where the implementation of CITES has only recently been enforced, such as Peru where the proportion of species in peril from trade is high,” the experts warn.
Numerous other threats loom over cacti, such as conversion of land for agriculture, and commercial and residential development.
Moreover, cacti habitats — which are most often arid areas — are often overlooked in conservation planning, the authors write. For example, according to the report, arid areas of Brazil, Chile, Mexico and Uruguay are hotspots for threatened cactus species. But while rich in biodiversity, “these areas are perceived as uncharismatic and unimportant,” the authors write.
“The results of this assessment come as a shock to us,” Barbara Goettsch, lead author of the study and Co-Chair of IUCN’s Cactus and Succulent Plant Specialist Group, said in the statement. “Their loss could have far-reaching consequences for the diversity and ecology of arid lands and for local communities dependent on wild-harvested fruit and stems.
“This study highlights the need for better and more sustainable management of cactus populations within range countries,” she added. “With the current human population growth, these plants cannot sustain such high levels of collection and habitat loss.”
- Goettsch B, et al. (2015) High proportion of cactus species threatened with extinction. doi:10.1038/nplants.2015.142