A whopping 38 percent of tree species are at risk of extinction worldwide, which would appear to threaten life on Earth as we know it, according to a report.

That's the warning from the Global Tree Assessment, which featured in a statement from the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

Issued to coincide with the United Nations' COP16 summit on biodiversity, held in the Colombian city of Cali, the report claimed that from 166,061 types of tree, 46,337 are now on the IUCN Red List.

IUCN Director General Dr Grethel Aguilar said: "Trees are essential to support life on Earth through their vital role in ecosystems and millions of people depend upon them for their lives and livelihoods.

"As the IUCN Red List celebrates 60 years of impact, this assessment highlights its importance as a barometer of life but also, crucially, as a unique tool guiding action to reverse the decline of nature."

For the first time, the majority of the world's trees have been listed on the IUCN Red List, revealing that at least 16,425 of the 47,282 species assessed are at risk of extinction.

Trees now account for over one quarter of species on the IUCN Red List and the number of threatened trees is more than double the number of all threatened birds, mammals, reptiles and amphibians combined. Tree species are at risk of extinction in 192 countries around the world.

"This comprehensive assessment presents the first global picture of the conservation status of trees, which enables us to make better informed conservation decisions and take action to protect trees where it is urgently needed," said Dr Malin Rivers, Global Tree Assessment lead at Botanic Gardens Conservation International, a Red List Partner.

"The work is a global effort, with over 1,000 tree experts involved. We need to continue to work together to scale up local, national and international tree conservation action to support people and the planet."

The highest proportion of threatened trees is found on islands. Island trees are at particularly high risk due to deforestation for urban development and agriculture at all scales, as well as invasive species, pests and diseases.

Climate change is increasingly threatening trees, especially in the tropics, through sea-level rise and stronger, more frequent storms. Addressing the threats trees face, habitat protection and restoration, as well as ex-situ conservation through seed banks and botanic garden collections are critical to prevent extinctions on islands and worldwide. Community action has already led to positive outcomes from the Juan Fernández islands to Cuba, from Madagascar to Fiji, the report said.

In South America – home to the greatest diversity of trees in the world – 3,356 out of 13,668 assessed species are at risk of extinction. Innovative approaches are needed to protect the high number of tree species in the region, where forest clearance for crop farming and livestock ranching are the largest threats.

The IUCN Red List also shows that the loss of trees is a major threat to thousands of other plants, fungi and animals. As a defining component of many ecosystems, trees are fundamental to life on Earth through their role in carbon, water and nutrient cycles, soil formation and climate regulation.

The Western European hedgehog has moved from Least Concern to Near Threatened on the IUCN Red List. The species' numbers are thought to have shrunk in more than half the countries where it lives, including the UK, Norway, Sweden, Denmark, Belgium, the Netherlands, Germany and Austria.

Nationally, numbers have reduced by an estimated 16-33% over the past ten years, with local studies also reporting declines of up to 50% in Bavaria, Germany, and Flanders, Belgium. Increasing human pressures, particularly the degradation of rural habitats by agricultural intensification, roads and urban development, are driving declines of the Western European Hedgehog.

"The assessment of all tree species has been a massive undertaking that has taken many years to complete and that needs to be celebrated," said Jean-Christophe Vié, Director General of Fondation Franklinia, which funded most of the Global Tree Assessment.

"It is still ongoing but we now know where to act to efficiently tackle the extinction crisis hitting the world's trees. There is no excuse not to act. With such a large number of threatened tree species, the task is huge but it has already started.

"Trees are seen as an easy fix to climate change and trees are planted everywhere but the way reforestation is done needs to be greatly improved."

Dr Eimear Nic Lughadha, Senior Research Leader in Conservation Assessment and Analysis at the Royal Botanic Gardens, Kew, added: "The significance of the Global Tree Assessment cannot be overstated, given the importance of trees to ecosystems and people. We hope this frightening statistic of one in three trees facing extinction will incentivise urgent action and be used to inform conservation plans."

Subscribe to Storyboard: A weekly newsletter bringing you the best of CGTN every Friday