Tennis-court-sized Tiny Forests cool city air by up to 6C
Earthwatch Europe has been planting Tiny Forests, dense native woodlands about the size of a tennis court, in UK schools, parks and unused council land since 2020. Its volunteers have recorded air up to 6 degrees Celsius cooler inside a three-year-old Tiny Forest than outside it.
In the 1970s the Japanese botanist Akira Miyawaki developed a way to restore native forest on degraded land. Only species that would grow there naturally are planted, the soil is loosened and enriched, and saplings go in densely, three to five per square metre, in four layers from shrubs to canopy trees. Competing for light, the trees grow upwards fast.
Since 2020 Earthwatch Europe has used the method in the UK through its Tiny Forest programme. Each Tiny Forest is about 200 square metres, roughly a tennis court, planted in urban spaces such as school grounds, parks and unused council land. A network of citizen scientists and Tree Keeper volunteers monitors them.
The early results are striking. In a comparison with Coventry City Council, 95 percent of Tiny Forest trees were alive after six months, while none survived in a traditional planting. A four-year-old wild cherry in Hammersmith Park reached 540 cm, growing more than 100 cm a year against a usual 30 to 60 cm.
The forests also help their cities. Earthwatch has recorded air temperatures up to 6 degrees Celsius cooler inside a three-year-old Tiny Forest than in the surroundings, and water soaking into the ground up to 28 percent faster, which reduces runoff. Surveys find bumblebees, butterflies, worms, frogs, newts and slow worms.
"For me, it's a great space for my wellbeing, to relax after a stressful day at work and do some weeding," said Mina, a Tree Keeper at New Road Park in London.
A patch of land the size of a tennis court can cool a street, soak up rain and give city children a forest to learn in.
Source: What is a Miyawaki forest? The science behind Tiny Forests (Earthwatch Europe).
Written by the HappyGood desk from the primary source linked above and checked against it. Every story links its source. Corrections: [email protected].
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