Olea europaea L. is an economically and ecologically significant species, for which accurate biomass estimation provides critical insights for artificial propagation, yield forecasting, and carbon sequestration assessments. Currently, research on biomass estimation for
Olea europaea L. remains scarce, and there is a lack
[...] Read more.
Olea europaea L. is an economically and ecologically significant species, for which accurate biomass estimation provides critical insights for artificial propagation, yield forecasting, and carbon sequestration assessments. Currently, research on biomass estimation for
Olea europaea L. remains scarce, and there is a lack of efficient, accurate, and scalable technical solutions. To address this gap, this study achieved, for the first time, non-destructive estimation of
Olea europaea L. biomass across individual tree to plot scales by integrating UAV-RGB (Unmanned Aerial Vehicle-Red-Green-Blue) imagery with the U
2-Net model. This study initially developed allometric models for
W-D-H,
CA-D, and
CA-H in
Olea europaea L. (where
W = biomass,
D = ground diameter,
H = tree height, and
CA = canopy area). A single-parameter
CA-based whole-plant biomass model was subsequently developed utilizing the optimal models. An innovative whole-plant biomass estimation model (UAV-RGB, U
2-Net Total Biomass, UUTB) that combines UAV-RGB imagery with U
2-Net at the sample-plot level was developed and assessed. The results revealed the following: (1) The model for
Olea europaea L. aboveground biomass (AGB) was
WA =
0.0025D1.943H0.690 (
R2 = 0.912), the model for belowground biomass (BGB) was
WB =
0.012D1.231H0.525 (
R2 = 0.693), the model for
CA-D was
D =
4.31427C0.513 (
R2 = 0.751),
CA-H model was
H =
226.51939C0.268 (
R2 = 0.500). (2) The optimal AGB model for
CA single-parameter was
WA =
1.80901C1.181 (
R2 = 0.845), and the model for BGB was
WB =
1.25043C0.772 (
R2 = 0.741). (3) The
R2 of
Olea europaea L. biomass, as estimated by
CA derived from the U
2-Net and UUTB models, was 0.855. This study presents the first integration of UAV-RGB imagery and the U
2-Net model for biomass estimation in
Olea europaea L., which not only addresses the research gap in species-specific allometric modeling but also overcomes the limitations of traditional manual measurement methods. The proposed approach provides a reliable technical foundation for accurate assessment of both economic yield and ecological carbon sequestration capacity.
Full article