One-third of world's trees now in danger of extinction

And according to the report, this figure is probably on the low side.

That is because species that are not well-researched (around 21 percent) are recorded as 'not threatened', whereas, in fact, many so-called 'data deficient-species' may also be close to extinction.

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

Elizabeth Maruma Mrema, chief of the UN-biodiversity convention (COP-15) in October, is currently leading the effort to get countries to commit to a global conservation effort in the coming decades.

"If we are going to achieve an ambitious transformation of our relationship with nature by 2050, tree conservation needs to be at the heart of our efforts to conserve ecological restoration," she said in response to this study.

As with most forms of natural degradation, the biggest threat to tree species is human activity. Over the past 300 years, global forest area has decreased by about 40 percent, and 29 countries have lost more than 90 percent of their forest cover.

Livestock farming and crop production together are by far the most significant cause of habitat loss, followed closely by timber logging, a considerable part of which is illegal.

The international criminal police organization (Interpol) estimates the value of illegal logging at between €42-€127bn per year, while estimates for legal logging are around €225bn.

Other emerging causes of habitat loss are climate change, extreme weather and rising sea levels.

The value of trees

The study makes an effort to show that trees are valuable to human life in a kaleidoscope of ways. Around 45 million people directly or indirectly work in forestry, earning a total yearly income of €490bn.

Trees provide medicine. People depend on trees for their mental and physical health and beautifying urban centres. Trees provide food, shelter, fuel. And in many parts of the world, trees remain centres for spirituality, identity and social life.

One of the examples the study highlights is Madagascar. The island nation suffers one of the highest rates of endangered trees in the world. But it has been found that strong intergenerational local legends are entwined with individual Baobab trees.

Emily Beech, a contributor to the study, told EUobserver that makes it hard to express the value of trees in a simple number.

"We included some numbers because that leads to political traction. I don't relate to them, but I can see why it might encourage political action."

Tree blindness

An additional challenge confronting conservationists is a phenomenon she called 'tree blindness'.

"A lot of the world is made up of trees and plants. But most people associate species extinction with beautiful animals like tigers or rhinos," she says. "People can relate to trees and plants, but there seems to be a disconnect between them and the products we derive from them." She points out that people especially overexploit the trees they need and love the most, often without realising it.

Sandalwood, for example, is used for candles and cosmetics. Overexploitation threatens all 18 species of sandalwood. Ebony, universally known and loved for its dark hue, is also threatened by illegal logging.

"More money is being spent on the preservation of animals than on trees. But what most people don't realise is that if we lose the tree, we lose everything: we lose the birds, the animals, the plants and fungi that depend on it."

The study names multiple solutions to tackle the problem. Top among them is funding for preservation and tree-planting programs. And the money needs to be directed towards trees that are most in danger.