Scientists Studying Earth’s Trees Issue Serious Warning to Humanity: ScienceAlert


From soaring coast redwoods to dinosaur-era Wollemi pines and firs that make perfect Christmas trees, even our most revered woody plants have a lot of problems.

But it turns out that the loss of some species will not only endanger local forests; it will threaten entire ecosystems, according to a new study.

Last year, a global assessment titled State of the World’s Trees discovered that a shocking third of all tree species are currently on the brink of existence.

This represents approximately 17,500 unique endangered tree species.

This is more than double the number of all threatened tetrapods (mammals, birds, amphibians and reptiles).

Some trees are so rare that only one known individual remains, such as the lone pine in Mauritius, Hyophorbia amaricaulis.

In a new paper, the same team of researchers behind the State of the World’s Trees publishes a “warning to humanity” on the consequences of these losses, supported by 45 other scientists from 20 different countries.

Conservation biologist Malin Rivers of Botanic Gardens Conservation International and his colleagues describe the many impacts these losses will have on our economies, livelihoods and diets.

Most of our fruit comes from trees, as do many nuts and medicines, with non-timber products accounting for approximately $88 billion in trade.

In the developing world, 880 million people depend on firewood for fuel and 1.6 billion people live within 5 kilometers (3 miles) of a forest, relying on it for food and a living.

In total, trees contribute about US$1.3 trillion a year to the global economy, but we destroy billions of them every year, clearing huge swaths of land for agriculture and development.

The trees are each their own little world, teeming with all kinds of single-celled and multi-cellular life forms, including other plants, fungi, bacteria, and animals. Lose a tree, and this whole world dies too. They often form the supporting base of the entire web of life around them.

In fact, half of all the animals and plants in the world depend on tree habitats.

“Habitat loss is often the loss of trees, that’s the root of that when we look at animal or bird extinction issues,” Rivers told Nature World News. “There’s no way to take care of all the other creatures out there if we don’t take care of the trees.”

As with all living systems, the loss of diversity makes all living connections more vulnerable.

Indeed, less variation means less diversity in immune response, in genes, and in responses to environmental conditions, which means less chance of surviving the many threats to the complex web of interactions that is life. on earth.

Some tree species offer unique interactions and cannot be replaced by other species.

This includes the distinctive Dragon’s Blood Trees (Cinnabar Dracaenai), remnants of ancient Oligocene groves, which are home to many other species that depend entirely on it, including many other plants and the gecko that pollinates it.

Thus, the extinction of a single species can cause a massive domino effect on everything that interacts with it, even if they are already rare.

The species that depend on our declining forests have already declined by around 53% since 1970, and more and more of the world’s forests are showing signs of increasing stress.

It doesn’t just impact the other trees of life they interact with.

Trees are also connected to Earth’s soil, atmosphere and weather – purifying our air, producing oxygen and making it rain. They store three quarters of the world’s accessible fresh water and more than half of its problematic carbon dioxide.

If you lose enough trees, our planet’s carbon, water and nutrient cycle will be disrupted.

“We show that diverse forests store more carbon than monocultures,” Rivers said. The Guardian.

“This is true for many ecological functions, not just carbon sequestration, but also providing habitat for animals, stabilizing soils, resilience to pests and diseases, resilience to storms and weather. By losing the diversity of trees, we will also lose the diversity of all organisms: birds, animals, fungi, microorganisms, insects.”

A few species of trees are lucky and able to take advantage of the rapid environmental changes we have caused, such as those infiltrating territories that fires have cleared. But many others are erased by the same processes.

Much more needs to be done to tackle this on a collective level, but we can all play a part by recognizing the importance of trees and fighting our own plant blindness. Earlier this year, researchers pointed out that fewer people than ever are taking botanical education in the UK at a time when we need plants more than ever.

Ahead of the UN biodiversity conference Cop15 in December, Rivers and his colleagues are urging leaders to better integrate trees into climate policies and provide them with greater protection. We all need to think about trees.

This research was published in Plants, People, Planet.


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