Steve Lewis share | DigitalVision | Getty Images

Nearly 30% of tree species in the wild are now critically endangered, with a variety of factors responsible for their decline, according to an analysis released Wednesday.

The report on the condition of the world’s trees, published by Botanic Gardens Conservation International, found that of the 58,497 registered tree species on the planet, 17,510 – or 29.9% – were threatened.

In addition, 4,099 are “potentially threatened” while at least 142 species are now extinct in the wild, according to the report.

The 29.9% figure does not believe that “data deficient” species or species that scientists do not have enough information about are threatened. If all species in this category were classified as endangered, the proportion threatened with extinction would rise to 51.3%.

“Assuming that species with a lack of data are just as likely to be threatened as any other tree species, we can estimate that 38.1% of tree species are classified as threatened,” the report said. Conversely, 41.5% of the species are not considered to be threatened.

“The main threats to tree species are deforestation and other forms of habitat loss, the direct exploitation of wood and other products, and the spread of invasive pests and diseases,” the report said. “Climate change also has clearly measurable effects.”

In addition to the latter, a statement by BGCI states that both climate change and extreme weather conditions represent “emerging threats to tree species worldwide”.

“If the world changes temperature and weather, many trees risk losing suitable habitats,” she added. “This affects species in both temperate and tropical habitats, with cloud forest tree species being particularly endangered in Central America.”

The report’s figures were based on data from various sources such as the International Union for Conservation of Nature Red List, scientific research and conservation assessments.

The threatened trees will be familiar to many and include oaks, magnolias and maples.

BGCI general secretary Paul Smith said the report was “a wake-up call to everyone in the world that trees need help”.

“Every species of tree is important – to millions of other tree-dependent species and to people around the world,” he said.

Trees are a crucial cog in the planet’s ecosystem. A report by the Food and Agriculture Organization of the United Nations said forests “provide water, mitigate climate change and provide habitats for many pollinators that are essential for sustainable food production”. Elsewhere, the IUCN says forests absorb about 2.6 billion tons of carbon dioxide every year.

While the BGCI report is sobering read, the organization also listed a number of measures that could be taken to “protect and bring back threatened species”.

These include: conservation of threatened species in seed banks and collections in botanical gardens; Increasing the availability of corporate and government funding for threatened tree species; the expansion of tree-planting programs; and expansion of “protected area coverage for threatened tree species that are currently not well represented in protected areas”.

Among those commenting on Wednesday’s findings was Sara Oldfield, the co-chair of the Global Tree Specialist Group.

“Trees are vital to our future and for a healthy world we need the diversity of tree species,” said Oldfield, who also contributed to the BGCI report.

“Each tree species has a unique ecological role. As 30 percent of tree species worldwide are threatened with extinction, we urgently need to take protective measures.”