This was originally posted on the London Prepared Blog, I’ve slightly adapted the original to cater for the audience of this blog.
This week is London Tree Week, part of RE:LEAF – the initiative to help protect and increase the number of trees in London.
Far from just standing there, trees offer many benefits from a resilience perspective. Here I investigate the important role that trees play in developing our own resilience to emergencies:
- Trees stabilise our soils and slopes – the root systems of trees, and other plants, hold together soils which would otherwise be gradually washed away by rainwater. Elsewhere in the world, trees offer protection against avalanches and landslips.
- Trees reduce flash flooding– the tree canopy intercepts rainfall which reduces the rate at which rainwater hits the ground, this reduces the likelihood of surface water flooding.
- Trees provide a buffer to extreme temperatures – on average forested land is 2-4 degrees cooler in the summer and 1-2 degrees warmer in the winter. This means they are natural helpers in our preparations to reduce the impact of Heatwaves and episodes of snow and ice.
- Trees reduce wind speeds – which can be a major source of building damage. Thanks to building regulations, large-scale damage or destruction is unlikely to occur as a result of wind speeds in the UK, but is has caused issues internationally.
- Trees reduce pollution – as well as their role in converting carbon dioxide to oxygen (which is important in reducing the rate of climate change), tress also help remove sulphur dioxide and nitrogen oxide, which are major components of acid rain. Have you noticed those trees with the patchy bark? The London Plane tree is type of sycamore which was extensively planted in Victorian London. When the pores of the tree trunk get clogged with pollutants, the tree sheds its bark, escorting the pollutants to the sewer system.
Downed trees and branches can impact on power lines or block roads, which can cause disruption. However it’s worth thinking about how much worse the disruption or damage could be if the tree hadn’t taken the brunt of the force.
For balance, it’s important to realise that trees can also contribute to, or provide a habitat for, some risks:
- In late 2012 scientists at the Food & Environment Research Agency (FERA) confirmed a number of cases of Ash Dieback, which can cause tree death, across Norfolk, Suffolk, Kent and Essex
- In 2006 the Oak Processionary Moth caterpillar was confirmed on trees in the London Borough of Richmond following an incidence of skin rash symptoms among local residents. There has since been a spread of this caterpillar to different areas of London.
However, if we make sure that trees are properly looked after and maintained, then they offer a range of hidden benefits which make us more resilient to many kinds of emergency.
Image Source: mtthwhgn.com