Rising levels of carbon dioxide threaten monarchs: study



[ad_1]

Atmospheric carbon dioxide fixation levels pose an unrecognized threat to monarch butterflies, reducing the medicinal properties of milkweed plants that protect insects emblematic of the disease, a study found

to hunt predators and parasites, and the plant is the only food of the monarch's caterpillars.

Researchers at the University of Michigan in the United States cultivated four species of milkweed with different levels of protective compounds, called cardenolides. the plants were grown under normal levels of carbon dioxide (CO2), and half of them were bathed, from dawn to dusk, in almost twice that amount. The study showed that the most protective plants of the four species of milkweed lost their medicinal properties when they were grown under high CO2, which resulted in a sharp decline in the monarch's ability to tolerate a common parasite.

The researchers looked only at how high levels of carbon dioxide change plant chemistry and how these changes, in turn, affect interactions between monarchs and their parasites.

"We have discovered an indirect mechanism until then unknown by which a continuous environmental change – in this case, increasing levels of atmospheric CO2 – can act on the disease. in monarch butterflies, "said Leslie Decker, first author of the study published in the journal Ecology Letters.

" Our results emphasize that they influence host-parasite interactions by altering the medicinal properties of plants " said Decker, who is now a postdoctoral fellow at Stanford University in the United States.

The results have broad implications, said Mark Hunter, ecologist at the University

Many animals, including humans, use chemicals in the environment to help them to control pests and diseases. Aspirin, digitalis, Taxol and many other drugs came from plants, he says.

"If carbon dioxide reduces the concentration of drugs in plants used by monarchs, it could change the concentration of drugs for all animals, including humans," Hunter said.

[ad_2]
Source link