Is Plant Extinction Crisis Worse Than Animals?

Dear EarthTalk: When we talk about “endangered species” we usually think of animal species, but someone recently told me that there was a worldwide crisis pertaining to the extinction of plants. Can you enlighten?

—Max Blanchard, East Islip, NY

plant extinction
The UK-based nonprofit, Plantlife, found that 15,000 of the 50,000 species of wild plants used in traditional remedies are being overexploited and are potentially headed for extinction. Pictured: Goldenseal, used as a multi-purpose remedy and grown in southeastern Canada and the eastern U.S., is one such threatened species. © James Steakley, Wikipedia

We may not realize it, but the health of the plant kingdom is crucial to the health of the planet and the animal life (which includes humans) it supports. “Through photosynthesis, plants provide the oxygen we breathe and the food we eat and are thus the foundation of most life on Earth,” reports the Center for Biological Diversity, an Arizona-based nonprofit dedicated to securing the future for endangered plants and animals throughout the world.

“Unlike animals, plants can’t readily move as their habitat is destroyed, making them particularly vulnerable to extinction,” says the Center. Habitat destruction—just one of the threats plants face—can lead to an “extinction debt” whereby even some plants that are plentiful now could disappear over time by being unable to disperse to new habitat patches. And global warming is already starting to exacerbate such problems. “With plants making up the backbone of ecosystems and the base of the food chain,” says the group, “that’s very bad news for all species, which depend on plants for food, shelter and survival.”

A 2009 report by the UK-based nonprofit, Plantlife, found that 15,000 of the 50,000 or so species of wild plants known for their medicinal qualities in traditional remedies are being overexploited and are potentially headed for extinction. The group says the fact that most people around the world—including some 80 percent of all Africans—rely on herbal medicines obtained primarily from wild plants underscores just how serious a problem a mass extinction of wild plants could be for humanity, let alone for the environment. Commercial over-harvesting does the most harm, though pollution, competition from invasive species and habitat destruction all contribute. “Commercial collectors generally harvest medicinal plants with little care for sustainability,” Plantlife reports, adding that shortages already exist in China, India, Kenya, Nepal, Tanzania and Uganda.

Another group, the International Union for the Conservation of Nature (IUCN), which compiles and maintains the famous “Red List” of endangered species around the world, found that a whopping 70 percent of the 12,000-plus plant species it has evaluated to date are threatened with extinction—despite the fact that each year about 2,000 new plants make themselves known to science. Of course, the organization only evaluates plants that are rare or have suffered major declines.

Meanwhile, researchers in the UK estimate that up to 33 percent of all flowering plants worldwide are threatened with extinction. “That percentage reflects the global impact of factors such as habitat loss,” says Lucas Joppa, the study’s lead author, who adds that climate change could increase the toll.

This worldwide threat to plants is just part of a larger biodiversity crisis, and the United Nations has declared 2010 “The International Year of Biodiversity” to raise awareness and encourage action to help stem the tide. The project’s website features listings of celebrations taking place around the world as well as resources for those who want to help spread the word and be part of the solution.