China’s “green wall”: planted forests grow 66% faster than natural ones

Chinese artificial forests, planted under the program “Great Green Wall”increase leaf area 66% faster than nearby natural forests. But scientists warn: rapid growth does not make plantations a complete replacement for old natural ecosystems.

China has been implementing the world’s largest reforestation program, known as “Great Green Wall”. Its goal is to contain the expansion of the Gobi and Taklamakan deserts, reduce dust storms and restore degraded areas in the north of the country.

Since 1978, it is estimated that approximately 66 billion trees. As he writes Live Sciencea new study shows that China’s planted forests are growing leaf area significantly faster than natural forests.

What exactly did the scientists measure?

The researchers used satellite data and an indicator Leaf Area Index — foliage area index. It shows canopy density and helps assess a forest’s ability to photosynthesize and sequester carbon.

According to the study, planted forests increased leaf area by approximately 66% fasterthan natural forests. Much of the difference is simple: man-made forests are younger on average, and young trees tend to grow faster than older ones.

But even after adjusting for age and local growth conditions, planted forests still showed an advantage of approximately 4.6%. The difference was especially noticeable in mixed and evergreen forests. He also writes about this Fertilizer Daily citing work published in Geophysical Research Letters.

Why artificial forests grow faster

There are several reasons. Firstly, such plantings often use fast-growing species, such as poplar and eucalyptus. Secondly, forests are actively managed: competing vegetation is removed, fertilizers are sometimes applied, trees are planted more densely and in a pre-selected pattern.

In addition, scientists suggest that young planted forests respond more strongly to rising CO₂ concentrations in the atmosphere. More carbon dioxide can speed up photosynthesis, especially in young and actively growing trees if they have enough water and nutrients.

This is where a favorite human pitfall comes in: if something grows fast, it seems like it is automatically “better.” But the forest is not a lawn near a business center. Quickly increasing green mass and building a sustainable ecosystem are different tasks.

Quick effect is temporary

The main limitation is age. According to the study, the benefit of planted forests peaks when the trees are about 30–40 yearsand after 40 years it begins to decline noticeably. That is, it is a strong short-term tool, but not an eternal carbon sequestration accelerator.

Natural forests grow more slowly, but continue to accumulate carbon over decades and centuries. Moreover, carbon is stored not only in leaves, but also in trunks, roots, dead wood, litter and soil.

As noted Techno-Sciencethe leaf area index is an important indicator, but it does not equal the total carbon stock. The leaves are clearly visible to the satellite, but the climatic value of the forest cannot be measured only by the green “cap”.

Why natural forests are irreplaceable

Natural forests support a much more complex system: many species of plants, fungi, insects, birds, mammals, soil microbiota, water regimes and disease resistance. A planting of fast-growing trees may look impressive from satellite heights, but be poor in biodiversity.

This is why scientists stress that mass reforestation may be useful for short-term CO₂ absorption, but it is not a substitute for protecting old natural forests. An old forest is not just a lot of trees. This is a system of connections accumulated over decades or centuries that cannot be reproduced by an order, a tender or a beautiful report from a drone.

A Chinese project shows that large-scale tree planting can quickly change the landscape. But if you rely only on artificial forests, you can get a green picture without a sustainable ecology. It’s very human: first destroy a complex system, then plant a simplified version and call it progress.

There is also a water problem

Such projects have another risk – water balance. Mass tree planting in arid regions can reduce water availability, especially if species with high water requirements are selected.

Reuters previously reported that China had completed the creation of a 3,000-kilometer green belt around the Taklimakan Desert, but pointed to remaining challenges: low tree survival, drought and the continued threat of sandstorms. Reuters: China completes green belt around Taklamakan.

Other studies have also warned that large-scale greening in China could change evaporation and the distribution of water across regions. In other words, planting a tree does not always automatically mean “helping nature.” Sometimes it is also taking water from grasses, soils, rivers or agriculture. Nature, as it turns out, does not like being repaired by a bulldozer and KPIs.

What does this mean for climate policy?

The Chinese experience is important not only for China. Many countries are banking on reforestation as a way to sequester carbon and mitigate climate change. New research shows that such projects can indeed produce quick green benefits and short-term increases in photosynthesis.

But it also shows the limits of this strategy. Young, established forests can quickly absorb CO₂, but long-term carbon storage, sustainability and biodiversity require protection of natural forests. One does not replace the other.

If climate policy boils down to the formula “cut down the old forest and plant a new one,” this is not restoration, but accounting magic. The carbon balance may look decent on paper, but the ecosystem is losing something that isn’t measured in a single line on the report: age, complexity, soil, species, and sustainability.

Main conclusion

China’s planted forests actually grow faster than natural forests in terms of leaf area: 66% on average and 4.6% faster even after adjusting for age and conditions. This makes the Great Green Wall an important tool for short-term carbon sequestration and combating desertification.

But rapid growth is not the same as a full-fledged forest. The benefit of artificial plantings wanes after 30–40 years, but natural forests remain essential for long-term carbon storage, climate resilience, soils, water and biodiversity.

The Chinese project shows the power of large-scale government planning. But it also reminds us of an unpleasant thing: nature cannot be completely replaced by an engineering project. Billions of trees can be planted. It is impossible to grow an ancient forest in one generation.

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