Modelling aboveground biomass using MODIS FPAR/LAI data in alpine grasslands of the Northern Tibetan Plateau

ABSTRACT

Aboveground biomass (AGB) is a vital variable in global carbon cycling and plays important roles in ecosystem structure and function in grasslands. Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 leaf area index (LAI) and fractional photosynthetically active radiation absorbed by vegetation (FPAR) data were used to model AGB in alpine grasslands in the Northern Tibetan Plateau. MYD15A2H (derived from the Aqua MODIS with a temporal resolution of eight days) FPAR/LAI with lower RMSE values (<18 g m⁻²) may have higher estimated accuracies than MOD15A2H (derived from the Terra MODIS with a temporal resolution of eight days), MCD15A2H (derived from the combination of Terra MODIS and Aqua MODIS with a temporal resolution of eight days) and MCD15A3H (derived from the combination of Terra MODIS and Aqua MODIS with a temporal resolution of four days) FPAR/LAI with higher RMSE values (>20 g m⁻²). The RMSE values (11.42–13.27 g m⁻²) in the open grazed areas were lower than those (17.46–17.56 g m⁻²) in fenced areas for MYD15A2H. Therefore, the estimated accuracies of AGB may vary among the four MODIS FPAR/LAI products and land use types in alpine grasslands of the Northern Tibetan Plateau.

Acknowledgement

We thank the editor and reviewers for their insightful and valuable comments, which greatly improved the quality of this manuscript.

Additional information

Funding

This work was supportedby the National Key Research Projects of China (2017YFA0604801; 2016YFC0502005), the National Natural Science Foundation of China (31600432; 41571042), the Science and Technology Plan Projects of Tibet Autonomous Region (Forage Grass Industry), Youth Innovation Research Team Project of Key Laboratory of Ecosystem Network Observation and Modeling (LENOM2016Q0002).