China's planted forests add leaf area faster than natural forests, study finds

Planted forests in China increased their leaf area 65.8 per cent faster than the country's natural forests, a team led by researchers at Peking University reported in the journal Geophysical Research Letters. The paper was published online on 28 May 2026, and its finding drew wide coverage in late June and early July 2026, including a report by Jagonews24 on 9 July 2026. Its authors are Yuhang Luo, Yuan Wang, Han Wang, Hongliang Wang and Jiansheng Wu, and its title is "Enhanced CO2 Response and Aging-Related Dynamics Drive a Greater Leaf Area Index Increase in China's Planted Forests in Comparison to Natural Forests".

News reports linked the finding to China's decades-long tree-planting drive in its dry north, which Live Science, in a report published on 30 June 2026, said had put 66 billion trees in the ground since 1978. That number comes from those reports, not from the study, which compared forests through satellite measurements of leaf cover rather than by counting trees. The coverage also pointed to an earlier study, published in Communications Earth & Environment in May 2025 by a team led by Kai Cheng of Peking University, which found that young natural forests in China were adding carbon above ground faster than young planted forests of the same age.

Yuhang Luo, the first author, is listed in the paper at the School of Urban Planning and Design of Peking University's Shenzhen Graduate School and at the school's Key Laboratory of Earth Surface System and Human-Earth Relations of China's Ministry of Natural Resources. Live Science described him as a landscape ecologist at Peking University in Shenzhen. The Jagonews24 report had called him a climate scientist. Han Wang and Jiansheng Wu are listed at the same Shenzhen school, Yuan Wang at the Department of Architecture of the National University of Singapore, and Hongliang Wang at the School of Public Administration of Inner Mongolia University. The paper appeared in volume 53, issue 11, of Geophysical Research Letters, a journal of the American Geophysical Union.

The question the team asked is set out in the paper's abstract. China's forests had gained a notable amount of leaf area, driven both by the expansion of planted forests and by the conservation of natural forests, but how the two kinds of forest respond differently to environmental change had remained unclear. Planted forests are those people deliberately create, such as the shelterbelts of northern China; natural forests grow without that kind of human intervention.

To compare the two fairly, the researchers combined leaf area index data with a statistical method called propensity score matching, which pairs planted and natural forest areas that share similar conditions, and with machine learning. Luo told Live Science that the work began from a gap in the models scientists use to project the climate. "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," he said. "So we felt it was important to clarify how these factors interact," he added, both for scientific understanding and for the models and assumptions behind real-world forest policy and carbon accounting.

Across China as a whole, planted forests increased their leaf area 65.8 per cent faster than natural forests, the abstract says; news reports rounded the figure to 66 per cent. The Jagonews24 report described it as China's planted forests running about 66 per cent ahead of nearby natural forests in leaf production. The paper's figure is about the rate at which leaf area grew over time, not about the total amount of leaves a forest carries.

Most of that gap reflected age. The planted forests in the study were on average 34 years old and the natural forests 57 years, and younger trees put on leaves faster. When the researchers compared forests of similar age and growing conditions, planted forests still grew 4.6 per cent faster. The difference was larger in mixed and evergreen forests, where the planted stands showed stronger responses to rising carbon dioxide in the air.

The advantage is not permanent. According to the abstract, the CO2-driven advantage of planted forests declines markedly after age 40, and Live Science reported that the gap peaks when planted trees are about 30 to 40 years old. Natural forests eventually overtake planted forests in the part of leaf-area growth that comes with age. The authors wrote that the planted forests' head start is stronger because they are younger, 34 years against 57, and more sensitive to CO2. They concluded that the findings highlight the role of planted forests in carbon sequestration and could help improve ecosystem models.

Business Today, in a report on 7 July 2026, summed up the same results: forests created under China's reforestation drive were expanding their leafy canopy about 66 per cent faster than naturally occurring forests, with most of the difference due to age and about 4.6 per cent remaining once forests of similar age and conditions were compared. It added the researchers' caution that rapid growth does not automatically mean long-term ecological success.

Leaf area index is the ratio of leaf area to the area of ground beneath it, in square metres of leaf per square metre of ground; for broad-leaved trees it counts the one-sided green surface of the leaves. It is widely used as an indicator of how fast plants are growing and changes with the seasons, usually peaking when new leaves appear. Live Science described it as a measure of canopy density and a key driver of carbon uptake, which is why satellite records of it are used to track how vegetation responds to climate.

Satellites had already shown China's part in a greener planet. In February 2019, a team led by researchers at Boston University, with co-authors at Peking University, reported in Nature Sustainability that satellite data for 2000 to 2017 showed a greening pattern strikingly prominent in China and India. China alone accounted for 25 per cent of the global net increase in leaf area while holding only 6.6 per cent of the world's vegetated area. In China, 42 per cent of the greening came from forests and 32 per cent from croplands, and the study concluded that human land use, including China's programmes to conserve and expand forests, was a key driver of the greening of the Earth.

Leaf area is still only part of the picture. A researcher who worked on reforestation models during his postdoctoral research at the University of Waterloo in Canada, and who was not involved in the study, told Live Science that the results made intuitive sense, since the spreading leaves of young, fast-growing trees could mean more carbon taken up. But he was not sure leaf area was the best measure of growth and carbon storage. "It's not a bad proxy, but it doesn't give you the full picture," he said. "The canopy is just the top of the tree and the carbon is stored in all sorts of different places like wood, bark, roots and soil." He pointed to another study of Chinese forests that found natural forests accumulate more carbon above ground than planted ones in their early years.

Much of the difference reflects how planted forests are managed, Live Science reported. They tend to feature fast-growing species such as eucalyptus and poplar and are often actively managed, with competing vegetation removed and in some cases fertiliser applied. These interventions reduce competition for light, water and nutrients and amplify the fertilising effect of rising atmospheric CO2, the report said. Business Today gave the same explanation, noting that such species are chosen for rapid growth of wood and leaves.

The CO2 fertilisation effect is the rise in the rate of photosynthesis, together with reduced water loss through the leaves, that plants show when the air holds more carbon dioxide. Its strength depends on the plant species, air and soil temperature and the supply of water and nutrients, and faster photosynthesis does not always turn into more growth or more stored carbon. The Peking University team found planted forests more sensitive to this effect than natural forests, especially in mixed and evergreen stands, and that is what the paper's title refers to as an enhanced CO2 response.

The Food and Agriculture Organization of the United Nations (FAO) separates planted forests into two kinds. In its Global Forest Resources Assessment 2020, plantation forests are intensively managed, made up of one or two species, even-aged, planted with regular spacing and established mainly for production. Other planted forests are not intensively managed, may resemble natural forests when they mature, and can serve purposes such as ecosystem restoration and the protection of soil and water. Worldwide, 44 per cent of plantation forests consist mainly of introduced species, the assessment found.

The tree-planting drive behind most of the coverage is the Three-North Shelter Forest Program, often called the Great Green Wall. Begun in 1978, it is a series of planted windbreak forest strips, or shelterbelts, meant to hold back the expansion of the Gobi Desert and to provide timber for local people. Its name refers to the three northern regions it covers: the North, the Northeast and the Northwest. The programme is planned to run until about 2050, when it is expected to form a green barrier about 4,828 kilometres long and in places up to 1,448 kilometres wide. At its launch, the aim was to raise forest cover in northern China from 5 to 15 per cent.

Live Science wrote on 30 June 2026 that China had planted 66 billion trees since 1978, with plans for 34 billion more by the middle of the century, as part of the Great Green Wall to slow the spread of the Gobi and Taklamakan deserts. Business Today put the number at roughly 66 billion and called the programme the world's largest afforestation initiative. The Times of India, whose report Jagonews24 drew on, used the figure "over 60 billion trees" in its headline of 7 July 2026, and the Bengali headline of the Jagonews24 report spoke of 66 billion trees. The figure was reported by these outlets; neither study counted trees, and the Peking University study covered all of China's planted and natural forests rather than the shelterbelt alone.

The Gobi is a large, cold desert and grassland region in southern Mongolia and northern China and the sixth-largest desert in the world. The Taklamakan lies inside the Tarim Basin in southern Xinjiang, bounded by the Kunlun Mountains to the south, the Pamirs to the west, the Tian Shan to the north and the Gobi to the east. Business Today summed up the programme's aims as reducing desertification, curbing dust storms, restoring degraded land and increasing carbon absorption. The Jagonews24 report likewise said planted forests contribute a great deal to preventing soil erosion and reducing dust storms, and that their quickly spreading green leaves help hold desert sand in place.

The work has had setbacks. In 2008, winter storms destroyed 10 per cent of the new forest stock, and the World Bank advised China to focus more on the quality of what it planted than on quantity. By 2009, China's planted forest covered more than 500,000 square kilometres, raising tree cover from 12 to 18 per cent and making it the largest artificial forest in the world. In November 2024, China reported that it had completed a green belt of about 3,000 kilometres around the Taklamakan Desert.

The second study in the Jagonews24 report was published on 5 May 2025 in Communications Earth & Environment, a Nature Portfolio journal, under the title "China's naturally regenerated forests currently have greater aboveground carbon accumulation rates than newly planted forests". Its first author, Kai Cheng, and most of its authors are at the Institute of Remote Sensing and Geographic Information System in Peking University's School of Earth and Space Sciences in Beijing; others are at Chengdu University of Technology, Southwest Forestry University, Nanjing University of Information Science and Technology and a Beijing technology company.

The team built growth models for China's forest types from 52,055 survey plots of the Seventh National Forest Inventory, carried out from 2004 to 2008. Each plot covered about 667 square metres and recorded the forest's origin, age and species. The researchers then used Landsat satellite images to map young planted forests and young naturally regenerated forests, defined as forests under 30 years old, and estimated how fast each was adding carbon to its trunks, branches and leaves, the carbon held above ground.

In 2020, China's young planted forests covered about 450,000 square kilometres with an average age of about 19 years, mostly in the south, southeast and north of the country. Young natural forests covered about 310,000 square kilometres with an average age of 16 years, mostly in the northeast, southwest and southeast. The average rate at which young natural forests added above-ground carbon was about 1.4 times that of young planted forests.

The main reason was the structure of the forest, especially the number of trees. Planted forests consistently had a much higher tree density than natural forests of the same age, and the more trees a planted forest held compared with a natural one, the further its carbon gain fell behind. The authors wrote that this challenges the common assumption that more trees directly mean more stored carbon: crowded trees compete for light, water and nutrients. Across both kinds of forest, temperature, and in particular how much it varied through the seasons, was the strongest influence on the rate of carbon gain, explaining 39.6 per cent of the spatial variation in planted forests and 28.2 per cent in natural forests.

The team also projected the carbon these young forests would hold by 2060, the year of China's carbon-neutrality target, if they stayed protected and undisturbed. Above-ground carbon in the young planted forests would rise from 992.5 to 1,542.3 teragrams, and in the young natural forests from 674.9 to 1,650.3 teragrams, so that although the planted forests held more carbon in 2020, the natural forests would hold more by 2060. A teragram is a million tonnes. This is the basis of the point in the Jagonews24 report that planted forests can green quickly while natural forests store carbon better over the long term.

China's forests had grown a great deal in the decades before the study. Statistical data cited in the 2025 paper show that China's forest area expanded from 117.12 million hectares in 1973 to 1976 to 179.89 million hectares in 2014 to 2018, and that the area of planted forest nearly doubled over that time.

A 2024 study in Nature Communications by many of the same Peking University researchers, published on 15 May 2024, used satellite and field data to trace China's planted forests from 1990 to 2020. It found that their area doubled, with the trend intensifying after 2000, and that the carbon they stored rose from 675.6 teragrams in 1990 to 1,873.1 teragrams in 2020, an average of about 40 teragrams a year. About 53 per cent of that increase came from the expansion of the planted area rather than from the growth of existing plantations, the study found.

In global terms, the FAO's Global Forest Resources Assessment 2020 put the world's forest area at 4.06 billion hectares, 31 per cent of the land, with more than half of it in just five countries: the Russian Federation, Brazil, Canada, the United States and China, which had 220 million hectares. Seven per cent of the world's forests, about 290 million hectares, were planted, and the planted area had grown by 123 million hectares since 1990. Asia had the highest net gain in forest area in 2010 to 2020, the assessment found.

Large-scale planting in China had drawn criticism well before 2026. Planting blocks of fast-growing trees of one kind reduces the variety of plants and animals a forest supports, and a lack of diversity makes trees more vulnerable to disease: in 2000, a single disease killed one billion poplar trees in Ningxia, setting back 20 years of planting. Research in reforested parts of the Loess Plateau found that exotic species planted at high density could worsen water shortages, because the forests drew more moisture from the soil than farmland did.

A study published in January 2023 on the first 40 years of the programme found that only one fifth of the forests that survived had become a forest stand within 10 years, and only one tenth were still alive after 40 years; shrubland fared better, with nearly half surviving after 10 years and a third still present in 2017. Critics have also argued that the dry climate and poor soils make it hard to keep trees growing in the long run, and that planting does not address causes of desertification such as overgrazing and unsustainable farming.

The 2025 Peking University study made a related point from the carbon side. It cited research showing that many plantations in China have stand densities above the optimal level, and a study of Masson pine (Pinus massoniana) plantations in southern China which found that denser planting lowered the average rate of carbon uptake. Planted forests are often dominated by a single species or a few, which can lower biodiversity and resilience to environmental stress, the authors wrote.

Luo told Live Science that planted forests are useful but not a substitute for natural ones. "Planted forests can be a powerful short-term tool for carbon uptake, but this advantage is temporary," he said. "For long-term carbon storage and resilience, natural forests remain irreplaceable." He said most global climate models were missing how different forest types take part in carbon storage. "Land use management works in more subtle and specific ways than we had assumed," he said. "It is not just about planting more trees. It is also about when you plant them, what species you choose, and how you manage them over time."

He hoped the findings would guide reforestation so that new forests do the most to slow climate change. "Our work offers a more practical guide for forest-based climate action: when to plant, what to plant, how long the benefits last, and what current models are getting wrong. We hope that helps people make better decisions," he said.

The 2025 study set out concrete steps for managing China's planted forests to store more carbon:

• thinning, which removes poorly growing or crowding trees so that the remaining ones grow more efficiently and store more carbon;
• planting at lower initial densities, to reduce early competition and help trees grow better in the long run;
• choosing species suited to local conditions, and mixing species with complementary traits, such as fast-growing pioneer trees with shade-tolerant ones, which earlier studies found raised carbon storage in mixed plantations;
• a balanced approach that draws on the strengths of both natural and planted forests.

The Jagonews24 report made the same point in its own words: what counts is not only how many trees are planted, since the growth of planted forests may slow as they age, and their long-term care calls for adding native species and managing how densely they grow.

Photo: wuqiang_beijing / Wikimedia Commons (CC BY 3.0). The top picture shows forest in Saihanba National Forest Park, Hebei Province, China, as background; it is not a picture from either study.

Sources: Jagonews24 (9 July 2026, drawing on The Times of India), Geophysical Research Letters (Luo et al., published online 28 May 2026), Live Science (30 June 2026), Business Today (7 July 2026), Communications Earth & Environment (Cheng et al., 5 May 2025), Nature Communications (Cheng et al., 15 May 2024), Nature Sustainability (Chen et al., 11 February 2019), FAO Global Forest Resources Assessment 2020 Key findings, Wikipedia (Great Green Wall (China), Leaf area index, CO2 fertilization effect, Gobi Desert, Taklamakan Desert).