Trees along the Great Green Wall are growing considerably faster than natural forests, scientists have found
Trees in China’s sprawling Great Green Wall project appear to grow faster than those in natural forests, a new study has revealed.
Around 66 billion trees have been planted for the Great Green Wall since 1978. It is set to expand even further – plans are underway to plant 34 billion more trees by the middle of the century.
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Scientists believe that these trees in China are responding better to rising carbon dioxide levels in our atmosphere and are absorbing carbon from the atmosphere.
To reach their conclusions, scientists used satellite data to track the leaf area index – a measure of canopy density and a key driver of carbon uptake – to determine how quickly different forest types grew.
They found a remarkable difference: planted forests increased their leaf area 66 per cent faster than natural ones. The majority of this difference could be attributed to planted forests being, on average, younger than natural ones. Young trees grow faster than older ones.
However, even when comparing forests of similar age and growing conditions, planted ones grew 4.6 per cent faster. Such differences arise from the way planted forests are managed, as they tend to feature faster-growing species such as poplar and eucalyptus.
The study found that growth advantage peaks at planted forests around 30 to 40 years in, before declining. In contrast, natural forests – although slower to develop – store carbon more steadily over time, making them vital carbon sinks for long-term climate resilience.
‘Planted forests can be a powerful short-term tool for carbon uptake, but this advantage is temporary,’ said the study’s author, Yuhang Luo. ‘For long-term carbon storage and resilience, natural forests remain irreplaceable.’
Why was the Great Green Wall created?
Around 3,600 square kilometres of China’s grassland are lost to the Gobi Desert each year, along with 2,000 square kilometres of topsoil. Such desertification can sweep dust across the country and into east coast cities, driving up air pollution and trapping particulates at ground level.
As such, the wall was created to slow the expansion of the Taklamakan and Gobi deserts and protect China’s grasslands.
Since 1978, strips and patches of trees have been planted in vast quantities across the north of China. They act as windbreaks against dust storms from the Gobi and Taklamakan deserts. As well as this, the trees help to stabilise sand dunes in some areas.
