Dark clouds over the cacti. Scientists predict extinctions

Cacti are associated with plants that are extremely resistant to lack of water. Scientists emphasize, however, that they also do not cope with rapid climate change. The cactus family has over 1,900 species, and most of them grow only in the Americas.

Because these plants are adapted to living in dry climates, it was thought that climate change would not threaten them. However, more and more data shows otherwise, said Pablo Guerrero Martin from Universidad de Concepcion in Chile.

It's not just the amount of rain that matters

So far, predictions about the future of plants have been based primarily on average temperature and average rainfall. The authors of the study point out that this approach may not show the full scale of the threat.

For cacti, it is not only the average conditions during the year that are crucial, but also how long the drought lasts and how severe it is. High temperatures further worsen the situation because they accelerate the drying of the soil and increase the plants' demand for water.

Scientists analyzed over 688,000 cactus observations. On this basis, they prepared forecasts for 993 species by the end of the century.

More endangered species than previously thought

Models that include extreme droughts show a much worse scenario than previous analyses. According to them, the area suitable for living will shrink for 66 percent. studied species. In models that did not take into account severe droughts, this was the case for 55%. species.

Much also depends on whether cacti will be able to move to areas with a more favorable climate. If they are unable to do this, as many as 84-85% may lose adequate living conditions. species. Even with the possibility of spreading up to 100 kilometers, 69-72% will be at risk. studied species.

The authors estimate that more than half of the cacti may lose at least a quarter of the areas where they currently have good conditions for survival. For 25-35 percent species loss may reach as much as 80%. such areas.

The most difficult situation in the Americas

The largest declines in the number of species are expected to include, among others: in Chile and on the country's border with Argentina, in Central America and in Peru, Ecuador and the central part of Colombia. In parts of Central America, the coast of Venezuela and northwestern Brazil, species numbers may be reduced by more than half.

Although these forecasts refer to the end of the century, it is worth noting that we are already observing phenomena that limit the range of plants, noted the lead author of the study, Michiel Pilliet.

Currently, 31% are considered at risk. cactus species - according to assessments by the International Union for Conservation of Nature (IUCN). Climate change is just one of the threats. Cacti are also harmed by the destruction of their habitats and illegal harvesting of plants.