Fun facts about trees you may not already know

December 3, 2023

Looking for something to get excited about? Then look no further!

In honour of National Tree Week, we have collated some weird and wonderful facts about trees which we hope will help you feel as grateful for and inspired by trees as we do.

1. Trees can communicate with and care for one another

Trees in a healthy forest care for each other by sharing resources through the Wood Wide Web; a complex, collaborative network of roots, soil, and fungi. The fungi send out super-fine tubes called hyphae, which permeate the soil and combine with tree roots at a cellular level, linking trees to their neighbours. This forms a huge underground network, otherwise known as the Wood Wide Web, which the trees use for communication and sharing resources. If one tree is sick, others can send sugars and nutrients to help. The relationship between the trees and the fungi is symbiotic; the fungi help the trees by sharing water and nutrients from the soil and, in return, the trees share sugars from photosynthesis with the fungi.

The University of British Columbia ecologist Suzanne Simard has found that these networks include older, larger, hub trees (or “mother trees”) that may be connected to hundreds of younger trees around them. Simard explained this further in a 2016 TED Talk.

Mother trees especially communicate with skin seedlings. The research found that seedlings that are kin to the mother tree receive more carbon than stranger seedlings.

We have found that mother trees will send their excess carbon through the mycorrhizal network to the understory seedlings […] and we’ve associated this with increased seedling survival by four times.
Suzanne Simard.

This network even goes so far as to ensure that If a tree is being eaten by an animal, it can release chemicals into the air that signal to the other trees in the forest that there is a threat. Those trees can then start producing toxic chemicals that will dissuade the animal from eating them, and protect them. Trees can also use chemicals to communicate with other animals. If a leaf-eating insect is chewing on a tree, the tree can send out a chemical signal to attract predators that feed on that particular insect.

The communication between the trees goes further than the forest network. In fact, a single mature oak tree supports more than 2,300 different species of invertebrates, birds, mammals and fungi! 300 of these species rely solely on the oak tree, which provides the sole habitat for these animals, plants and fungi.

2. They can have a monumentally positive impact on our changing climate…

Forests have their own localised climates and can help moderate extremes of heat and cold and store a lot of water. This means that trees can help cities adapt to extreme heat by providing shade and cooling surface temperatures by up to 12°C in some areas. They can also help with flooding, slowing the flow of water, absorbing water, and reducing soil erosion. Trees can help protect our environment from extreme temperatures and enable the people and animals that live in cities to cope better.

3. …and make the air more breathable

Hedgerows along roadsides can provide wildlife corridors and reduce air pollution, reducing ‘black carbon’ by as much as 63%, helping make the air cleaner and more breathable, but how does this work?

We’re glad you asked. A tree is, very simply, made up of leaves, stems, a trunk and roots. Through photosynthesis, leaves pull in carbon dioxide and water and use energy from the sun to convert this into chemical compounds such as sugars that feed the tree. As a by-product, oxygen is produced and released by the tree, making our atmosphere breathable. It is proposed that one large tree can provide a day’s supply of oxygen for up to four people.

4. They can also store massive amounts of carbon

The UK has 123,000 ancient and veteran trees and more ancient oak trees than the rest of Europe combined. It is these long-established woods which can store more carbon per hectare than other woods. They make up 25% of UK woodland but hold 36% of woodland carbon. The sheer amount of ancient woodland in the UK has monumental benefits for our environment; the Woodland Trust reports that these ancient woods currently hold a huge 77 million tonnes of carbon, and, in addition to this, absorb around 1.7 tonnes each year.

5. Trees create more green space and can positively impact our mental health

This may sound like an obvious one, but given that 84% of people in the UK currently live in urban areas, getting access to green space has never been so important; especially as trees make us happier and healthier. Studies suggest that the phytoncides that trees produce help to reduce mental and physical stress, anxiety, and depression in people when we breathe them in.

A fantastic example of this is the Japanese art of forest bathing, a term which represents a physiological and psychological exercise called Shinrin-yoku. This practice offers both a remedy to stress but also inspires reconnection with the natural world.

One of the really interesting things we found is that exposure to greenspace significantly reduces people’s levels of salivary cortisol – a physiological marker of stress. Forest bathing is already really popular as a therapy in Japan, with participants spending time in the forest walking around.
Twohig-Bennett

6. The oldest tree in the world is said to be 4,853 years old!

Image source

Seen in the above picture this Great Basin Bristlecone Pine, known as Methuselah, is thought to be the oldest living thing. This tree is located in Eastern California and it’s monumental age has been determined by exploring tree-ring data. To put its age into context, if estimated accurately, this tree would have stood at the time of the Ancient Egyptians.

7. Tree rings can indicate climate changes

The local environment and latitude can affect the length of a tree’s growing season and how a tree grows, as can aspects such as water availability. For example, if a tree has grown in an area where water is scarce, then the thickness of its rings will indicate when its growing season was longer; it will be longer during warmer times, and shorter during cooler times.

The study of the growth of tree rings is known as dendrochronology and it can demonstrate and reconstruct past climates, which is known as dendroclimatology.

A tree ring, representing one year, consists of two layers:

A light coloured layer: this type is formed when the tree is growing, which typically occurs in the spring and early summer, which is typically thicker because the tree is growing.
A dark coloured layer: this type forms when a tree is smaller or thinner because tree growth is slow. This typically happens at the end of summer and autumn.

In the tropics, trees grow year-round and consequently do not have dark and light alternating rings. In contrast, trees in a cooler climate, with more defined seasons and growing periods have differing ring patterns.

A final word…

A multitude of organisations across the UK and worldwide have taken part in another fantastic National Tree Week. We enjoyed delving into the history and significance of National Tree Week and hope you had a good time reading the highlights of our favourite tree facts and exploring the beauty of trees through poetry and art. National Tree Week may have come to an end, but our appreciation for trees certainly hasn’t. As we move into winter, we hope you’ll join us in our new-found appreciation for trees, with all their beauty and complexity.