Native woods and trees provide the means to tackle the significant environmental crises of our time. Here are a few key benefits based on facts from the Woodland Trust.
Trees and climate change
Trees are helpful in:
- Mitigating climate change – trees and their ecosystem (soil and plants) capture carbon from the atmosphere through photosynthesis and lock it up for centuries.
- Adapting to climate change – trees prevent flooding, reduce pollution, reduce urban temperatures and maintain the health of soils.
Trees and flooding
Extreme rainfall events arising from climate change increase the risk of flooding. Trees help reduce the accumulation of water in several ways:
- Their canopies intercept the rush of delivery to the ground.
- The soil beneath them is more permeable to water than hard surfaces such as asphalt.
- The deep roots of trees enable water to penetrate the soil.
- Dead material accumulates within rivers slowing their flow rate.
Trees and air pollution
Clean air is vital for the health of ecosystems; humans are part of these ecosystems. The biggest threat to clean air in the UK is vehicle emissions; power plants, industry, agricultural processes and domestic burning also contribute. Nitrogen dioxide (NO2) and fine particulate matter (PM2.5) are two of the most harmful pollutants; the latter can penetrate the lungs and enter the bloodstream.
Trees and air pollution interlink in two ways:
- Nitrogen air pollution disrupts woodland ecosystems by stripping trees of protective lichens and reducing less resilient woodland flowers.
- Trees and plants can protect people in urban areas from poor air quality by forming a barrier between people and the polluted air and capturing tiny particles on their leaf surfaces.
There is much scope to improve air quality in towns and cities as canopy cover is currently only 16% on average.
Trees and air temperature
As climate change results in increasing air temperature and heatwave frequency, urban areas will greatly benefit from tree planting and green spaces. Trees not only offer shade, but water evaporation from the soil and leaves has a cooling effect facilitating a fall in ambient temperature.
Trees and soil health
Soil is possibly the most valuable resource on our planet; it is the lifeblood of all plants and many animals. Over 94% of our food comes from the soil. It contributes enormously to locking in carbon, accounting for 69% of the carbon stored in forests.
Trees play a crucial part in soil health through:
- Protecting valuable topsoil from erosion by intercepting rainfall that lowers splash erosion, binding soil to improve water absorption, and acting as a wind-breaker.
- Soil creation when organic matter such as leaf litter and fallen/dead branches decompose.
Trees and biodiversity
Biodiversity is another crisis of our time. The UK is in a poor state, with 41% of all species declining since the 1970s. Woodlands provide a home for much wildlife; for example, an oak tree will support about 2,300 species all by itself! Native trees (originated in the region from which they are grown) are more valuable to conservation than non-native ones, owing to the balance of the ecosystem derived over many hundreds or thousands of years.
Planting trees is an excellent way to allow nature to flourish and encourage ecosystem restoration. Smaller woodlands need to get bigger and link to a network of nature-friendly habitats.
Trees and human health
Forests benefit our mental health. Enjoying the calming atmosphere of woodlands is known as forest bathing (shinrin yoku). It originated in Japan and encompasses being present and mindful within the woodland setting.
The Woodland Trust
The Woodland Trust are the UK’s largest woodland conservation charity, striving for a land rich in woods and trees. In the UK, woodland cover stands at just 13%, compared to the European average of 37%. The trust is supporting the ambition of 19% coverage by 2050 set by the Committee of Climate Change to meet the challenges of the biodiversity and climate crises.
The Woodland Trust has planted 55 million trees since 1972 and aims for another 50 million in the next 5 years – that is some expansion of ambition! They are the caretakers for over 1000 woodlands. Creating woodlands is central to their activities, but they also restore ancient woods by removing non-native trees, which make up 40% of ancient woodlands. Age determines when a tree becomes ancient; this varies with species, e.g., fast-growing birch trees could be classed as ancient at 150 years old, whereas a yew tree could be as old as 800 years of age. Campaigns to protect woodlands and trees are another Woodland Trust activity; threats include climate change, inappropriate developments such as HS2, pollution, a growing population, and diseases and pests.
One of their locations is the Young People’s Forest at Mead. Once a coal mine, the 500-hectare site has been planted with ~250,000 trees. As part of the #iwill campaign promoting youth social action, children and young people (10-20 years) have been developing the woodland to create a place for themselves and their community to enjoy. I spoke to Sabaha Hussein on the podcast about her experiences at Mead whilst on a gap year placement.
Trees are to be cherished
It can be easy to take our trees for granted, but if we stop for a moment and acknowledge their existence, we can relish the magnificence of trees. Then we can seek to nurture these awe-inspiring plants and expand their coverage. Alternatively, the facts on how they can help protect our planet are hopefully sufficiently persuasive.