The role of trees

There is a growing awareness of the importance of trees, as they form an essential part of our ecosystem here on land. One such role is as habitat for a multitude of species, for example in the UK oak trees provide the necessary living conditions for approximately 2000 species - with 700 of these species living exclusively on oak trees. (Oak trees: kings of biodiversity)

Trees are also well documented for their ability to sustain and regulate water within their root systems. This plays a crucial role in enhancing conditions for wildlife in forests, gardens, and urban areas. As well as slowing the rate of water runoff in favour of drainage and storage within the soil (The role of trees in water circulation). Like all plants, trees produce oxygen necessary for all animal and human life. They do this by absorption of light, CO2 (carbon dioxide) and water during photosynthesis.

The role trees play in sequestering excessive CO2 is critical to capturing this green-house gas in order to tackle climate change. It has been measured that a single tree can absorb between 10 kg and 40 kg of CO2 per year. This of course varies depending on the tree size, species (due to growth speed), the quality of the soil, sufficiency of water as well as other factors.

It is important to note that planting trees on its own is nowhere near enough to stop and reverse the effects of climate change. A study published by researchers at the Federal Institute of Technology in Zurich recommended that at least an additional one trillion trees would be needed to capture just two thirds of the carbon we are currently releasing into the atmosphere (Can planting billions of trees help tackle climate change? - BBC Science Focus Magazine).

Extensive reforestation as well as many other actions will have to be taken altogether to address this global problem, with The Climate Change Committee advising that 19% of the UK must be covered by trees if we hope to achieve net zero by 2050 ( A beginners' guide to planting trees and fighting the climate crisis, Trees and forests, The Guardian ).

Another important function of trees is their role of enriching soil with nutrients and organic matter. This ability is key to prevent or reverse soil erosion. Soil erosion is a process where a healthy soil containing billions of micro-organisms changes over time to become a lifeless dirt, losing the ability to support many lifeforms.

This phenomenon is well documented in modern agriculture, where overusing once arable land by intensive grazing or monocropping, often with the additional use of chemicals leads to the gradual loss of the ability of micro-organisms to recover.

Whether trees are added to agricultural land or if farmland is repurposed as woodland, the introduction of trees could reverse this erosion through the decomposition of foliage. You may have noticed that a healthy forest is not easy to walk through, this is because a healthy forest is made up of roughly 60% dead wood and 40% living trees. The dead wood is present in all stages of decomposition which is the recycling mechanism of organic matter. Hence why plenty of fallen trees and rotting trunks covered in moss are found in forests which are considered healthy.

This is not an exhaustive list. However, one more equally important role of trees is how humans have historically utilized their presence to add benefit to our own lives. Whether that is climbing a tree, gathering fruit from its branches, sitting in its shade or simply their aesthetic properties; with their various shapes and sizes, trees appear beautiful to human eyes with many people describing that the sight of trees help them to calm and relax.