d) The organization which has revealed that more than 60,000 species of trees are available globally. The BCGI (Botanical Gardens Conservation International), a charity that has compiled the list of trees on the basis of data gathered from its network of 500 member organizations.
c) The researchers claim to have collected information over a period of two years from sources including over 500 published contents and 80 experts in the BCGI's network.
a) BGCI, in collaboration with the International Union for Conservation of Nature, identified 60,065 tree species currently living on Earth.
b) Of that number, more than half were found to only occur in a single country, which could suggest an increased vulnerability to threats, said the authors of the database.
