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
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,"...