The health of millions could be at risk because medicinal plants used to make traditional remedies, including drugs to combat cancer and malaria, are being overexploited.
“The loss of medicinal plant diversity is a quiet disaster,” says Sara Oldfield, secretary general of the NGO Botanic Gardens Conservation International, told New Scientist.
Most people worldwide, including 80% of all Africans, rely on herbal medicines obtained mostly from wild plants. But some 15,000 of 50,000 medicinal species are under threat of extinction, according to a report this week from international conservation group Plantlife. Shortages have been reported in China, India, Kenya, Nepal, Tanzania and Uganda.
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,” the Plantlife report says. “This can be partly through ignorance, but [happens] mainly because such collection is unorganised and competitive.”
Medicinal trees at risk include the Himalayan yew (Taxus wallichiana), a source of the anti-cancer drug, paclitaxel; the pepper-bark tree (Warburgia), which yields an antimalarial; and the African cherry (Prunus africana), an extract from which is used to treat a prostate condition.
The solution, says the report’s author, Alan Hamilton, is to provide communities with incentives to protect these plants. Ten projects in India, Pakistan, China, Nepal, Uganda and Kenya showed this approach can succeed.
Sources: The Times Of India