A third of world's tree species at risk of extinction

Nearly one in three tree species are at risk of extinction due to agriculture, logging and livestock farming, a report has found.

In the first study of its kind the assessment looked at the state of the world's trees and found, of the nearly 60,000 tree species, 30% are at risk of extinction.

The study used the work of the Global Tree Assessment over the last five years, in which 60 institutions and more than 500 experts examined the extinction risk for the world's 58,497 tree species.

One in five tree species are directly used by humans for food, fuel, timber, medicines, horticulture and other uses.

Even though trees are valuable to people, at least 142 species are recorded as extinct and many more are disappearing because of over-use and poor management.

The top threats are being cleared for agricultural crops, cutting down for timber and cutting forests for livestock.

Climate change is also a rising threat, with increased temperatures and weather changes affecting the habitat.

About 180 tree species are threatened by rising sea level and severe weather including magnolias in the Caribbean. The increased risks of fire are a threat to trees in Madagascar and a risk to US oak species.

The report warns that more than 400 species are on the brink of extinction as they have fewer than 50 individual trees remaining in the wild.

The research published by Botanic Gardens Conservation International (BGCI) also highlights hope for conserving trees as 64% of all tree species can be found in at least one protected area.

BGCI are calling for the protected areas for threatened tree species to be extended, at-risk trees to be looked after in botanic gardens and for more money from businesses and the public to be use on tree conservation.

BGCI secretary general Paul Smith said: "This report is a wake-up call to everyone around the world that trees need help."