6 things you didn’t know about rainforests

This article has been updated.

When it comes to rainforests, it’s hard not to get caught up in superlatives and extremes.

They are the world’s oldest and most biologically diverse terrestrial ecosystems. They are home to some of the world’s oldest and largest trees. The world’s longest river and largest drainage basin flows right through them.

But if those often-repeated nuggets aren’t enough to convince you of their importance, here’s five more rainforest facts you may not have heard.

When we think of rainforests, our minds tend to turn to the great tropical rainforests of the Amazon or Congo. Far less talked about are temperate rainforests, found mainly in coastal and mountainous regions where temperatures are less sticky.

Compared to regular forests, rainforests tend to be composed of tall, evergreen trees, and have a high amount of rainfall - more than 80 inches a year. But there is nothing to say they have to be in hot places.

Temperate may not be as biologically diverse as their tropical counterparts, but the slower growing, longer living plant environment makes them the densest store of above-ground carbon in the world. Giant Redwoods in the Pacific Northwest are the world’s oldest and biggest trees, capturing more carbon than any other species.

One thing they do unfortunately have in common with tropical rainforests is deforestation - temperate rainforests are thought to be more threatened than tropical rainforests.

In the UK, research suggests that the temperate rainforests which used to mostly cover the west coasts have the potential to be partially restored. The remaining forests could double in size in a generation if they were allowed to naturally regenerate, Guy Shrubsole of the Lost Rainforests of Britain Campaign, told The Guardian.

We all know rainforest fauna and flora has had a huge influence on biomedical science, helping us develop new treatments for diseases like cancer. In fact a quarter of all modern medicines come from tropical forest plants. But it is also having an impact on physical sciences, engineering and technology.

Inspired by the unique way pitcher plants trap insects, researchers at AdaptiveSurface Technologies have created a repellent surface coating for containers. Snake skin has inspired more grippy shoe soles which could reduce the risk of falling among older adults. Geckskin mimics gecko’s feet to create reusable tape which sticks to multiple surfaces without damage. Chameleons have inspired vibrant new inks for 3D printing. And ants in the Amazon have inspired algorithms for self-driving cars.

The world’s forests sequestered about twice as much carbon dioxide as they emitted between 2001 and 2019. And tropical rainforests are the most important carbon sink of all - collectively sequestering more carbon than temperate or boreal forests.

But deforestation and declining rainforest health are having a significant impact on their effectiveness as a carbon capture mechanism. Of the world’s three largest tropical rainforests, only the Congo has enough standing forest to remain a strong net carbon sink.

As a way to remove carbon from the atmosphere, these nature-based solutions outstrip any engineered offering currently available. So successful are they, scientists are working on various ways to artificially reproduce photosynthesis. These include creating enzymes with artificial components and new materials inspired by lichen which combine fabricated polymers and loofah sponges.

This underlines the importance of conserving fragile rainforests, and restoring damaged ecosystems, benefitting both biodiversity and carbon sequestration.

Rainforests have been home to Indigenous People for millennia. These forest-dependent communities have developed intricate relationships with their environment, relying on forest resources for food, shelter, and medicine.

The Rainforest Alliance recognizes that these communities are often the best guardians of the forest, achieving conservation results that rival or surpass government-run protected areas.

Indigenous peoples’ and local community lands cover a third of the land on Earth - and remarkably 91% of these lands are in good or fair ecological condition. But the symbiotic relationship extends beyond mere survival; many tribal peoples have deep cultural and spiritual connections to the forest, viewing it as an integral part of their identity.

Community-centered conservation projects, like those supported by the Rainforest Alliance, aim to balance human needs with environmental protection. These initiatives often involve transferring forest management control to local communities, promoting sustainable resource use, and developing sustainable rural livelihoods that incentivize conservation.

Such approaches not only preserve biodiversity and support carbon sequestration but also protect valuable medicinal plants and other natural resources. By empowering forest-dependent people to become stewards of their environment, these projects demonstrate that human interaction with rainforests can be a powerful force for conservation rather than destruction.

Agriculture is the largest single cause of deforestation. This includes large-scale livestock ranching and plantations growing soy, palm oil, rubber, coffee, tea and rice.

As well as the environmental impact of deforestation, there is also a huge social impact, with concerns about working conditions in some areas.

However, many of the world’s rainforests are considered ‘wet deserts’, in that they grow on extremely poor soils, low in nutrients and are therefore not that suitable for agricultural use.

The reason the forests are so lush is in fact the rapid nutrient cycling - the goodness from decaying wood and leaves is processed very efficiently by bacteria, fungi and termites. This recycling happens so quickly that few nutrients ever reach the soil, leaving it nearly sterile.

But deforestation is leading to the savannization of the Amazon, according to the Brazilian scientist and meteorologist Carlos Nobre, who has spent three decades fighting for the rainforest. Only the double impact of reaching zero deforestation, alongside limiting global warming to 1.5C, can prevent savannization from happening, Nobre told Mongabay. "That’s why this immense region is very close to its point of no return."

Rainforests are not just lush landscapes; they are intricate ecosystems providing vital services that sustain life on Earth.

These forests act as natural water filters, purifying and maintaining fresh water supplies through their complex root systems.

The process of transpiration, where trees release water vapor, plays a crucial role in the water cycle, influencing rainfall patterns far beyond forest boundaries. This "flying river" effect contributes to flood and drought buffering, helping to stabilize regional climates.

As well as being powerhouses of carbon storage, the dense vegetation and rich soils of rainforests contribute to soil erosion control and nutrient cycling, maintaining soil health and fertility.

These forests are biodiversity hotspots, hosting an incredible array of plant and animal species, many of which are yet to be discovered.

Indigenous communities and organizations like the Rainforest Alliance recognize the importance of sustainable harvesting practices that preserve these ecosystem services while supporting local livelihoods.

By maintaining the delicate balance of oxygen turnover, carbon sequestration, and water regulation, rainforests effectively act as the planet's life support system, underscoring the critical need for their conservation.