Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (10): 1289-1304.DOI: 10.17521/cjpe.2022.0226

Special Issue: 遥感生态学

• Research Articles • Previous Articles     Next Articles

Assessment of vegetation productivity under the implementation of ecological programs in the Loess Plateau based on solar-induced chlorophyll fluorescence

XUE Jin-Ru, LÜ Xiao-Liang*()   

  1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China
  • Received:2022-06-02 Accepted:2022-09-12 Online:2022-10-20 Published:2022-09-21
  • Contact: *Lü Xiao-Liang(
  • Supported by:
    National Natural Science Foundation of China(73041901293);National Natural Science Foundation of China(42071328);Fundamental Research Funds for the Central Universities(24520212452021125)


Aims Based on the solar-induced chlorophyll fluorescence (SIF), this study was conducted to reveal the benefit of vegetation productivity in the revegetation region with a significant increase in land surface greenness under the large-scale implementation of ecological programs in the Loess Plateau.

Methods By interpreting satellite-observed terrestrial greenness changes and land use/cover dynamics, we first identified the spatial distribution of revegetation and existing vegetation in the Loess Plateau in the last 20 years. Then, using SIF and meteorological data, the gross primary productivity (GPP) of the revegetation and existing vegetation was calculated according to the revised mechanistic light response (rMLR) model. Finally, we adopted the comparative analysis approach to compare the differences in GPP of the revegetation based on the SIF observations.

Important findings Our results indicated that the ecological programs have made a widespread increase in land surface greenness in the Loess Plateau. In the period 2001 to 2020, the area of revegetated forest was 35 000 km2, accounting for 7.42% of the total area, whereas revegetated grassland area was 110 000 km2, accounting for 25.25% of the total area. Overall, the photosynthetic capacity and vegetation productivity of the revegetated forests were lower than that of existing forests in the Loess Plateau, while revegetated grassland was higher. GPP of the revegetated forest was equivalent to 83.86% of the existing forest, and GPP of the revegetated grassland was equivalent to 121.10% of that of the existing grassland. At the same leaf area index (LAI) level, GPP of revegetation and existing vegetation showed differences that GPP gap increased as LAI became higher. Revegetation transformed from bare land showed the lowest vegetation productivity, whereas forest growth and grassland restoration from cropland were the optimal land use/cover transition pattern for the revegetated forest and revegetated grassland, respectively. LAI increasing rate and restoration time also affected the productivity of revegetation, revegetated areas with higher LAI increasing rate showed more extensive productivity benefits. Vegetation productivity of revegetated forest increased with standage, while revegetated grassland with shorter restoration periods showed higher productivity. Overall, although ecological programs have widely increased vegetation cover and biomass in the Loess Plateau, however, there exists a certain gap in GPP between the revegetation and existing vegetation areas (especially in forests), thereby affecting the ecological benefits of the ecological programs.

Key words: ecological programs, revegetation, solar-induced chlorophyll fluorescence (SIF), gross primary productivity (GPP), the Loess Plateau