Despite their ability to thrive in conditions many living things find unbearable, cacti are in decline. Like many plant and animal species that are inching towards extinction, loss of habitat is a major factor, particularly as wild spaces are converted for agricultural purposes. But the member of the plant family Cactaceae faces another big threat: the illegal plant trade.
When we think of the victims of illegal wildlife trade, we often think of elephants and rhinos, with the high demand for tusks and horns. Or perhaps we think of big cats and cute monkeys destined to become clandestine pets. Collectable cacti is less likely to come to mind. But thorns aside, cacti are quite a charismatic and iconic plant, and many species produce prized blooms.
According to a new study published by the International Union for the Conservation of Nature in the scientific journal Nature Plants, one of the dominant drivers of extinction risk is "the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections.”
The authors of the study evaluated 1,478 species of cacti, and found 31 percent to be threatened. A high concentration of threatened and endangered cacti can be found in southern Brazil’s Rio Grande do Sul and Uruguay’s northern Artigas region.
The threats cacti face vary somewhat by region. In coastal areas of Mexico’s Baja California and in parts of the Caribbean, residential and commercial development is also a major threat. Collecting cacti for the plant trade is more concentrated along the coasts of Chile and Brazil.
Cacti are most commonly used in ornamental horticulture, but some species are also eaten or used in traditional medicine. The researchers found that 86 percent of the cacti used for the ornamental plant trade are taken from the wild, and much of this trade happens illegally. The Guardian reports that for some species, a single cactus may sell for up to $1000 USD in Europe or Asia.
One challenge to conservation, the authors note, is that hotspots of threatened cacti are unlikely to overlap with other endangered species. Threatened birds, amphibians and mammals are likely to live in more temperate climates than the arid regions where cacti thrive. The researchers say cacti hotspots should be taken into account for land management and conservation purposes.
The authors also call for greater enforcement of the treaty that prohibits the international trade of endangered wildlife, the Convention on International Trade in Endangered Species (CITES).