Zheng Xiao, Zhu Jiaojun, Wang G Geoff, Yan Qiaoling, Sun Tao, Song Lining, Gao Tian, Sun Yirong, Li Xiufen, Yang Kai, Zhang Jinxin, Yu Lizhong, Qi Ke, Zhao Lanlin, Lu Deliang, Lu Zhanyuan
CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
Qingyuan Forest CERN, National Observation and Research Station, Shenyang, 110016, China.
Sci China Life Sci. 2025 Feb;68(2):314-327. doi: 10.1007/s11427-024-2705-4. Epub 2024 Dec 20.
China's Three-North Protective Forest Program (TNP) is the world's most ambitious afforestation project (ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a range-wide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range (4.07 million km) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%, and 53.6%, respectively. However, only 40.1% of the 471,113 km afforested area was established between 1978 and 2022. The well-established shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions (TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composite ecosystems.
中国三北防护林工程（TNP）是世界上最具雄心的造林项目（1978年至2050年持续进行），旨在通过造林和再造林增加森林覆盖率，保护农业，减少土壤侵蚀，并控制荒漠化。尽管三北防护林工程已经进行了45年，但其原理和效果仍不确定。在此，我们通过分析来自10000多个卫星图像场景和50000多个实地调查地块的数据，对三北防护林工程进行了全面评估。在研究期间，三北防护林工程的范围以及防护林带、乔木林和灌木林的定义发生了变化，但我们使用了最初的三北防护林工程范围（40.7万平方公里）和1978年的定义，以保持一致性、可比性和全面性。三北防护林工程使森林覆盖率从1978年的5.05%提高到2022年的9.69%，其中乔木林、灌木林和防护林带分别增加了42.5%、184.4%和53.6%。然而，在1978年至2022年期间造林的471113平方公里面积中，只有40.1%得到了稳固确立。稳固确立的防护林带使作物产量提高了4.3% - 9.5%，但三北防护林工程地区（TNR）所有农田中只有10.2%得到了保护。水力侵蚀造成的土壤侵蚀总面积减少了447363平方公里，其中61%的减少归因于三北防护林工程。三北防护林工程使荒漠化减少了15%，这主要是由于造林成功率低以及草原面积大幅减少。三北防护林工程的总碳固存为1.96Pg C。此外，三北防护林工程地区的蓄水量呈下降趋势，但三北防护林工程的贡献率仅为7.8%。我们的结果表明，林业生态工程项目在干旱和半干旱退化土地的管理和恢复中是可行的，但必须注意充分考虑水资源的生态承载能力，使物种与立地相匹配，加强造林后管理，以及保持复合生态系统之间的平衡。
