The genus Quercus oak is one of the largest genera of the tree families. There are over 400 species and many new species are described every year. Most oak trees are large trees up to 20 to 30 meters in height, but the genus also includes small shrubs that grow in dry, sandy soil in the western United States or in the mountains of Mexico.
The origins of oaks can be traced back to 90 countries, especially the Northern Hemisphere, and the countries with the largest number of species are Mexico with 164 different species, China with 117 species, the United States with 91 species, and Vietnam with 49 species.
More than 100 experts have so far spent 5 years researching 430 species of oak, 230 of which have never been evaluated before. They have identified the oak species most at risk of extinction in a new report, The Red List of Oaks 2020.
The most striking conclusion is that 31 percent of oak species are in the danger zone, which is higher than mammals (26 percent) and birds (14 percent). The report says the countries with the largest number of endangered oak species are Mexico (32 species), China (36), Vietnam (20) and the United States (16), and it is also no coincidence which countries have the most indigenous oak species.
At least 41 percent of oak species have reason to be concerned about their chances of survival because they fall into the categories of “endangered,” “endangered,” “endangered,” “sensitive,” or “lack of data”.