Global study says 1 in 3 tree species at risk of extinction
That works out to 17,500 different species of tree that could be wiped from the Earth's surface.
Nearly one in three tree species are at risk of extinction, largely due to agriculture, logging and livestock farming, a report warns.
The Menai whitebeam, which has just 30 trees growing in its North Wales home, is one of hundreds of tree species which are on the brink of vanishing altogether, the first ‘state of the world’s trees’ report warns.
The assessment of how the world’s nearly 60,000 tree species are faring has found 30%, or 17,500, of them are at risk of extinction, with well-known species such as magnolia among the most threatened.
Oaks, maple and ebonies are also at risk, according to the report published by Botanic Gardens Conservation International (BGCI).
The study compiles work from the Global Tree Assessment over the last five years, which has seen more than 60 institutions and more than 500 experts examine 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.
But despite trees’ value to people, at least 142 species are recorded as extinct and many more face extinction because of over-exploitation and mismanagement.
The top threats are clearances for agricultural crops, logging for timber, and clearing forest for livestock, the assessment warns.
Climate change is also a rising threat, with many trees at risk of losing areas of suitable habitat as the temperatures increase and weather changes, with cloud forest species in Central America being at particular risk.
There are also at least 180 tree species directly threatened by sea level rise and severe weather, including magnolias in the Caribbean, while increasing risks of fire are a major threat to trees in Madagascar, and a risk to US oak species.
The report warns that more than 440 tree species are on the brink of extinction, as they have fewer than 50 individuals remaining in the wild, including the Menai whitebeam and the Mulanje cedar in Malawi, with just a few remaining individuals on Mulanje Mountain.
Islands have the highest proportion of threatened trees, with 69% of trees on the UK Overseas Territory of St Helena at risk of extinction, and 59% of those found in Madagascar.
In Europe, 58% of native European trees are threatened with extinction in the wild, with whitebeams and rowan the most at risk, while Brazil has the highest number of threatened tree species.
Dipterocarpaceae species are at risk from palm oil plantations in Borneo, while timber extraction threatens ebony in Madagascar, and mahogany and rosewoods across the Caribbean and Brazil.
Magnolia and camellia species are threatened from unsustainable plant collection for commercial uses, pests and diseases are causing severe decline to ash populations in the UK and North America, and oaks are threatened by deforestation, particularly in South and Central America, the report said.
But it also highlights hope for conserving trees, revealing two thirds (64%) of all tree species can be found in at least one protected area, and about 30% can be found in botanic gardens, seed banks or other collections.
BGCI is calling for governments and experts to extend protected area coverage for threatened tree species, ensure all at-risk trees where possible are conserved in botanic gardens and seed banks, and increase public and corporate funding for the issue.
In the report, the organisation also urges the expansion of tree planting schemes – with targeted planting of threatened and native species – and increased global collaboration to tackle tree extinction.
BGCI secretary general Paul Smith said: ‘This report is a wake-up call to everyone around the world that trees need help.
‘Every tree species matters – to the millions of other species that depend on trees, and to people all over the world.
‘For the first time, thanks to the information provided by the state of the world’s trees report, we can pinpoint exactly which tree species need our help, so policymakers and conservation experts can deploy the resources and expertise needed to prevent future extinctions.’
Jon Paul Rodriguez, chairman of the International Union for Conservation of Nature’s species survival commission, said: ‘For the first time, the state of the world’s trees (report) provides a comprehensive breakdown of our world’s trees.
‘Knowing where they are and why they are threatened is the first step towards acting for their conservation.
‘Despite the worrying data, I look forward to future state of the world’s trees reports, where I hope to learn of the increase in the number of known species and the decline in the proportion facing high extinction risk, due to the success of premeditated, coordinated global conservation action.’