UAV-based aboveground biomass estimation via trait-mediated pathways in a cultivated Leymus chinensis grassland.

Lidong Cao,Yu Fu,Tianhang Zhao,Dekun Meng,Xiaoting Pan,Wei Sun

Published 2026 in Journal of Environmental Management

ABSTRACT

Aboveground biomass (AGB) in cultivated Leymus chinensis grasslands is strongly influenced by irrigation, nitrogen fertilization, and mowing, yet many UAV-based AGB models rely mainly on spectral indices and random data splits, which can overestimate generalization under spatiotemporal dependence. Here we test whether adding management information and ground-measured structural traits improves UAV-informed AGB estimation in a plot-based, management-intensive system. Using a 3-year factorial experiment (12 water-nitrogen-mowing treatments) with UAV multispectral imagery, we built LightGBM models integrating spectral indices, management factors, and structural traits. A plot- and year-independent, target-optimized split was used to balance AGB and treatment distributions between training and test data. Mixed-effects models and structural equation modeling were used to quantify management interactions and trait-mediated pathways. Nitrogen fertilization increased AGB by 40-80%, while frequent mowing weakened the synergistic effect of irrigation and nitrogen. The best model achieved R2 = 0.73 on the fixed test set; external validation performance declined (temporal R2 = 0.54; spatial transferability CV R2 = 0.56) when key structural traits (canopy height and leaf area index) were unavailable, highlighting that transferability depends on feature availability. Structural traits contributed 52% of total importance, management main effects 24%, and spectral indices 20%. These results support management-relevant AGB monitoring in cultivated grasslands while clarifying current scalability limits.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-66 of 66 references · Page 1 of 1

CITED BY

  • No citing papers are available for this paper.

Showing 0-0 of 0 citing papers · Page 1 of 1