China has managed to quantify all of its trees through LIDAR sensors (“Light Detection and Ranging”, a system that uses laser pulses to measure distances and create 3D maps of an environment) and artificial intelligence algorithms, representing a milestone in the study of forest resources and ecological planning.
This advancement allows for obtaining accurate data on forest density and distribution, offering a crucial tool for environmental conservation and management.
How were all the trees in China counted?
The collected information was processed with specialized software and complemented with satellite data, generating a detailed forest map.
Some key figures:
- Scanned area: 1,400 km².
- Resolution: 100 meters per pixel.
- Estimated number of trees: 142.6 billion, equivalent to 100 trees per inhabitant.
Operation of LIDAR and big data in forest study
The LIDAR technology measures distances with great precision, allowing the evaluation of height and distribution of trees. When applied from the air, its operation is complemented by:
- Differential GPS to accurately locate points.
- Inertial navigation systems to calculate exact positions.
- Lidar360 geospatial software to detect and classify plant structures.
The Ninth National Forest Resources Inventory (2014-2018) had already identified a high tree density, with more than 1,000 trees per hectare in many regions. However, the new model offers greater precision and spatial analysis capabilities.
Distribution of forests in China
The number of trees is not uniform across the country. A higher concentration in the northeast and southwest has been identified, especially in provinces such as:
- Sichuan, Yunnan, Guangxi, and Heilongjiang (almost a third of the national total).
- Tibet (Xizang) with 1,980 trees per inhabitant.
- Yangtze River basin, southeast, and southwest, as the most forested areas.
- Northern and northwestern regions, where vegetation is scarce due to the advance of the Gobi Desert.
Accuracy of the study and technical limitations
Despite its great precision, researchers point out that some trees may not have been counted, especially:
- Small trees under dense canopies.
- Incomplete coverage in lower levels of the plant canopy.
- Lack of integration of ground data in the software.
A possible solution is to combine airborne data with ground scanners, which would increase vertical resolution and allow for obtaining a more complete image of the ecosystem.
China’s plans for forest management
The new forest map has practical implications in environmental projects such as the Great Green Wall, a belt of vegetation aimed at halting desertification in northern China. Since 1978, this program has planted more than 66 million trees, with the goal of reaching 100 billion by 2050.
Thanks to LIDAR, plantation areas can be selected with greater precision, allowing for:
- Avoiding reforestation in places with low ecological viability.
- Selecting species adapted to the specific environment.
- Maximizing the survival rate of planted trees.
- Minimizing the impact on existing ecosystems.
Additionally, this new map allows for more precise estimates of carbon absorption, monitoring of forest health, and planning for fires, pests, or droughts.
China strengthens its position in global reforestation initiatives, such as Trillion Tree, which aims to plant one trillion trees worldwide.
