The benefits of trees in urban landscapes
Trees in urban landscapes play a vital role in making our cities more sustainable.
Our cities are expanding rapidly, and this expansion should only take place with a proper land planning strategy, otherwise it will result in damaging effects on forests, landscapes and green spaces in and around our cities. But trees in urban landscapes can help to mitigate some of the negative impacts and social consequences of urbanisation, thus making our cities more resilient to change.
Here are the ways trees in urban landscapes can help make our cities more sustainable.
They produce oxygen
Trees produce oxygen, an element which is fundamental to our existence on this planet!
In a single season, one mature leafy tree can produce enough Oxygen to allow 10 of us to breathe. This is most important of all in densely populated and polluted areas like cities, with average Oxygen levels expected to be at least 6% lower.
Trees act as ‘carbon sinks’
Trees play an important role as what we call ‘carbon sinks’. This is the storing of carbon as part of the carbon cycle and is a key part of helping to mitigate the effects of climate change.
In a year, a single mature tree can absorb up to 48 pounds of carbon dioxide. It’s thought that globally our forests absorb 40% of man-made CO2 emissions before it reaches our outer atmosphere where it can trap more heat. Because of their size and density, trees are much better at this than smaller plants.
It’s estimated that 2,367,000 tonnes of carbon are stored in London’s trees alone, with an estimated value of £6.1 billion to the capital and £130 million in wider benefits.
Trees in urban landscapes clean our air
It’s well known that trees absorb Carbon Dioxide from the air, but that’s not the only air-purifying they get up too. Trees also soak up a surprising range of other pollutants and toxins generated by human activity. These include nitrogen oxides, ozone and sulpher oxides. They also filter fine particles such as dust, dirt or smoke out of the air by trapping them on leaves and bark. In the modern world, this is more vital than ever; air pollution – particularly in urban areas – means the air we breathe is reaching (or exceeding) toxic levels.
While all trees do this, the most successful ones are those suited to their location, require little management, or have long lives and are more disease resistant.
They help protect us from flooding
Did you know a single mature, leafy tree can absorb up to 450 litres of water through its roots every day? In addition, trees also capture rainwater on the surface of their leaves. Roots also reduce soil erosion in the ground and slow the filtration of water into our city drainage networks.
This is particularly important in cities where a large proportion of surface is made up of impermeable materials, such as paving or tarmac. When we get a sudden downpour, this can quickly cause flash flooding if the water has nowhere to go. This has become known as stormwater management and has seen the rapid rise of sustainable urban drainage systems, known as SuDs.