Researchers have estimated that 31 percent of the world’s oak tree species are threatened with extinction. A new report, The Red List of Oaks 2020, provides unprecedented details on the distribution of oak trees, population trends, and the dangers that they face.
Among the 430 oak species found worldwide, 32 species are threatened in Mexico, 36 in China, 20 in Vietnam, and 16 species in the United States. The proportion of endangered oak trees is higher than the global threat levels for mammals or birds.
Dr. Murphy Westwood is the director of Global Tree Conservation at The Morton Arboretum. “As we were evaluating the extinction risk of these hundreds of species over the past several years, it became clear how dire the situation is for oaks,” said Dr. Westwood.
“We finally have a complete picture of the state of the world’s oaks, so conservationists worldwide can take informed action to save oaks from extinction.”
The major threats to oak trees in the United States are invasive pests, diseases, and climate change, while the greatest hazards in Southeast Asia are deforestation and urbanization, according to the report.
The Arboretum and Botanic Gardens Conservation International (BGCI) have now established the Global Conservation Consortium for Oak (GCCO), partnering with botanical gardens, arboreta, universities and government agencies around the world to create a network of experts and institutions to protect threatened oaks globally.
“More than 2,300 species of bird, mosses, fungi, insects, lichens and mammals are recorded as using native oaks for food and shelter in the U.K., and the same will be true for the 113 species of oak now threatened with extinction,” said BGCI Secretary General Paul Smith. “The loss of just one of these tree species has catastrophic consequences for hundreds of other species.”
The Red List of Oaks 2020 was derived from five years of analysis and consultation with more than 100 researchers, including experts at the International Union for Conservation of Nature (IUCN) Global Tree Specialist Group.
“The comprehensive assessment of all oak species is a major achievement,” said Craig Hilton-Taylor, Head of the IUCN Red List Unit. “Having this information about such an ecologically and economically important group of trees is vital for informing conservation efforts.”
The initiative represents The Morton Arboretum’s contribution to achieving one of the 16 targets of the Global Strategy for Plant Conservation: to have an assessment of the conservation status of all known plant species by the end of 2020.