In recent decades, the rapid growth of China’s forest carbon sink has often been attributed to large-scale afforestation. However, our latest research reveals a more critical yet frequently overlooked driver: the management of existing forests. Rather than the continued expansion of forest area, improved management of current forests has been the primary force sustaining the growth of China’s forest carbon sink over the past two decades.
Imagine a landscape already covered by mature forests. Early large-scale tree planting transformed barren hills into green landscapes—an essential transition from nothing to something. Yet once forest cover stabilizes, whether forests can become healthier and more productive depends far more on management practices, such as forest tending, than on persistently planting trees on increasingly scarce open land. Our findings show that China is now at precisely this stage. After decades of extensive afforestation, land suitable for new planting has become limited. The engine of recent carbon sink growth has quietly shifted from “area expansion” to “forest management.”
Quantifying Human and Natural Influences
To identify the key drivers of carbon sink growth, we developed a new analytical framework that disentangles human activities from natural factors such as climate change. Our results indicate that existing forests dominate recent increases in carbon sink, contributing far more than newly planted forests during the same period. This is largely because the area of existing forests detected by remote sensing (1.77–2.23 million km²) is much larger than that of newly established forests (about 0.34 million km²).
More importantly, carbon sink growth driven by human activities accelerated significantly after 2010. This acceleration is largely hidden within improved management of existing forests rather than further land-use expansion.
Uncovering the Power of “Non–Land-Use-Change” Management
We classify human activities into two categories: land-use change through afforestation, and ecosystem management that enhances forest function without altering land cover, such as forest tending and mountain forest restoration. Our analysis shows that the contribution of the latter is three times greater than that of the former, highlighting that improving forest quality is more important than creating new forest area.
Which management measures matter most? We identify investments in forest tending and mountain forest restoration as the two most effective approaches. In southern China’s forest regions in particular, forest management dominates both the magnitude and acceleration of national anthropogenic carbon sinks. Overall, the total effect of forest management on carbon sink growth is 4.14 times that of afforestation.
Insights from Cost Effectiveness
One might ask whether afforestation delivers higher carbon gains per unit area. Our results confirm that it often does. Why, then, not continue expanding afforestation at scale? The answer lies in constraints of land availability and cost. Suitable land for afforestation has declined sharply, leaving limited potential for increasing total carbon sinks through area expansion alone.
In contrast, existing forests cover vast areas. Even modest per-area improvements in carbon sink can accumulate into substantial gains at the national scale. Cost–benefit comparisons make this even clearer: when measured as carbon gains per dollar invested, forest tending delivers up to 34 times the return of afforestation. This demonstrates that strengthening the management of existing forests is a far more efficient and economically viable pathway toward carbon neutrality.
The Broader Story and Future Outlook
This study is akin to mapping a national-scale “carbon sink contribution map,” requiring the integration of massive remote-sensing datasets, climate records, and detailed statistics on forest management practices, along with new methodologies to disentangle complex causal relationships. When the evidence consistently points to “management over afforestation,” it offers not only a new interpretation of China’s ecological restoration achievements, but also critical guidance for other countries—especially those that have completed large-scale afforestation and entered a period of stable forest cover.
China’s forests are transitioning from simply “becoming green” to truly “becoming better.” This story reminds us that the next phase of ecological restoration should shift attention from planting new trees to carefully nurturing every existing forest. It is not only a scientific insight, but also a reflection on how humanity can coexist more wisely with nature while addressing climate change.
For more scientific details, we invite you to read the full study: https://doi.org/10.1038/s43247-025-03176-2.