Study Finds China's Great Green Wall Trees Grow Faster Than Natural Forests
Research using satellite data shows that trees planted in China's Great Green Wall increase leaf area faster than natural forests, though their long-term carbon storage may be limited.
China’s decades-long Great Green Wall project, which began in 1978 and aims to halt desert expansion, has resulted in a marked increase in forest cover across the Gobi and Taklamakan regions. Satellite analysis reveals that the leaf area index of the planted trees is expanding about 66 % faster than that of comparable natural forests.
The study, published in Geophysical Research Letters, compared canopy density of the artificial forest with that of native woodlands. While younger trees generally grow more quickly, the researchers found that even when matching age and site conditions, the planted trees grew roughly 4.6 % faster.
"Planted forests are widely used in climate mitigation strategies, but most global ecosystem models do not distinguish between forest types or represent age-related dynamics adequately," said lead author Yuhang Luo, a landscape ecologist at Peking University in Shenzhen.
The growth advantage peaks when the trees are 30 to 40 years old and then declines, whereas natural forests maintain a slower, steadier growth rate that supports longer-term carbon sequestration.
"Planted forests can be a powerful short-term tool for carbon uptake, but this advantage is temporary. For long-term carbon storage and resilience, natural forests remain irreplaceable," Luo added.
The findings suggest that while the Great Green Wall has helped reduce dust storms and improve air quality, its role in climate mitigation may be limited compared with preserving and restoring natural forests.
