Scientists deploy precision tools to revive mangrove wetlands nationwide

The Ministry of Natural Resources has unveiled an accelerated ecological framework for the 15th Five-Year Plan period (2026–30), mandating a shift toward systematic governance and precision marine restoration powered by standardized, high-tech engineering toolkits.

At the center of this national strategy is a newly cataloged mangrove restoration technique developed by the Third Institute of Oceanography. The system was recently selected by the Ministry and the National Forestry and Grassland Administration as one of 35 proven innovations anchoring China's latest ecological catalog, which spans 10 critical fields from invasive species control to carbon monitoring.

Researchers in Fujian province are already employing this holistic "coastal armor" approach to ecological restoration.

When preparing to restore more than 13 hectares of mangrove forest on a mudflat in Ningde, they did not immediately reach for saplings. Instead, they began by giving the coastal area a comprehensive assessment.

"Just like a doctor running examinations before treatment, we test soil particle size, seawater salinity and tidal water levels, and measure the elevation of the mudflat," said Chen Shunyang, an engineer at the Third Institute of Oceanography of the Ministry of Natural Resources.

"Only by this physical checkup can we determine whether, where, and how to plant the mangrove — securing the survival and growth performance of mangroves," Chen said, adding that armed with these data, the team can draw up a customized restoration design for each site.

At the Xiatanwei restoration site in Xiamen, Fujian province, a composite plant community is well established. What was once a degraded shoreline is now a thriving marine ecosystem — a transformation that the researchers described as "putting multiple layers of armor on the shore" by combining tree-type and shrub-type mangrove species for plantation.

"In previous restoration practices, single-species plantation made the mangrove a solo fighter. Now, trees and shrubs resist waves together — the tall trees reduce the main force of wind and waves, while the shrubs further contribute to the wave attenuation, stabilizing the sediment and providing more habitats for benthic fauna," said Chen Guangcheng, a researcher at the institute.

The recognition of the mangrove restoration technique rests on a growing track record of ecological transformation. Chen Jiahui, an associate researcher of the institute, described the restored wetland as "a bustling marine paradise", with tree canopies serving as "top-floor terraces" for birds and insects, trunks and branches providing climbing corridors for snails and crabs, and understory shrubs offering more attachment space for snails.

Chen Guangcheng also emphasized the composite plant community's importance in enhancing carbon sequestration.

"Traditional single-species planting relied solely on the tree canopy for photosynthesis, leaving the space below unused. In the composite mangrove communities, both the upper canopy and understory shrubs contribute to photosynthetic carbon sequestration, while the complex aboveground structure reduces the tidal exportation of fallen leaves to increase organic matter supply for soil carbon accumulation, further enhancing the wetland's role in carbon sequestration," Chen Guangcheng said.

To measure soil carbon stock, the team developed a method to remove the roots from different depth layers along the soil cores, preventing living roots from being double counted as soil organic carbon.

This could improve the precision of mangrove carbon stock estimation, providing a reliable foundation for ecosystem carbon sequestration accounting.

Building on the long-term research and practices, researchers have established a carbon sequestration monitoring and accounting framework that underpins the national project methodology for mangrove afforestation under China's voluntary greenhouse gas emissions reduction program.

limenghan@chinadaily.com.cn