More than a fifth of the evolutionary history of flowering plants is at risk of extinction, a study published in Science by researchers from the Royal Botanic Gardens, Kew and the Zoological Society of London.
consulted by The DayGerardo Ceballos González, a Mexican ecologist recognized for his pioneering work in biodiversity conservation, said that this study is the first global evaluation of this plant group, which allows us to measure the magnitude of the crisis.
“The study confirms that the extinction crisis is global and affects all groups: plants, animals and other organisms. What we are experiencing is the mutilation of the tree of life. We are not only losing species, we are losing evolutionary history,” said Ceballos.
To estimate what percentage of evolutionary history is under threat, scientists used the EDGE (Evolutionarily Distinct and Globally Endangered) metric, which combines a species’ risk of extinction with its degree of genetic uniqueness within the tree of life.
This work revealed that flowering plants face almost twice the threat of extinction as jawed vertebrates. In addition, it identified 9,945 unique and threatened species that require priority attention for their conservation, since many of them belong to long and isolated branches of the tree of life, with few or even no close relatives.
Unique and ancient lineages
Examples of this are Amborella trichopodawhich separated from the rest of the flowering plants about 130 million years ago, and Ginkgo biloba, only descendant of a lineage more than 300 million years old.
“These are unique and ancient lineages that represent evolutionary processes from tens or even hundreds of millions of years ago. If they are lost, all that history disappears,” added Marie-Stéphanie Samain, from the AC Institute of Ecology (Inecol), in Pátzcuaro, Michoacán, in a separate interview.
EDGE scores for 335,497 flowering plants were calculated from molecular data and the IUCN Red List of Threatened Species, and were complemented by computer models to estimate danger in those not assessed. According to the study, protecting just 5.9 percent of them would protect half of all threatened evolutionary history.
Felix Forest, research leader in spatial phylogenetics at Kew, who led the study, said that this tool allows us to identify irreplaceable and threatened species that often go unnoticed.
Among the most vulnerable are: Hondurodendron urceolatuma dioecious tree with scattered populations in a mountain range in Cusuco National Park, Honduras, as well as the Seychelles medusa tree, the annual succulent Kewa acidavarious magnolias and the so-called “smelliest plant in the world”, Amorphophallus titanum.
Among the endangered plants with known uses for humanity, vanilla stands out (Vanilla planifolia), an orchid native to Mexico and the basis of one of the most appreciated aromas in the world.
Vanilla faces threats such as habitat loss and the extraction of wild specimens for cultivation and research. “In addition, there are very few clones of this orchid, which makes it particularly vulnerable to diseases,” Samain said.
In the country, vanilla is classified under special protection in the official standard NOM-059, which reflects its level of risk.
“Mexico has about 25 thousand species of plants. If we continue the trend, thousands are in danger. The impact is not only on vanilla, but on hundreds of cacti, pines and agaves,” concluded Ceballos.