## 3 Results and Discussion
### Comparison of the Results of Different Partitioning Methods
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Month** & **TR2.2.2** & **CEC** & **MREA** & **FVS** \\ \hline Solution Ratio & TR & 7 & 62.18 & 96.16 & 67.63 & 62.99 \\  & & 8 & 50.40 & 91.06 & 57.59 & 50.54 \\  & & 9 & 49.45 & 78.62 & 48.90 & 48.36 \\ \hline Daily Average & TR & 7 & 6.06 & 3.16 & 5.35 & 4.56 \\  & & 8 & 6.13 & 4.43 & 5.64 & 4.64 \\  & & 9 & 5.36 & 3.55 & 4.90 & 3.86 \\ Ev & 7 & 1.65 & 2.88 & 2.30 & 2.14 \\  & & 8 & 1.42 & 1.73 & 0.91 & 1.90 \\  & & 9 & 1.58 & 2.33 & 1.45 & 2.49 \\ TR/ET & 7 & 78.62 & 56.20 & 69.90 & 68.07 \\  & & 8 & 81.18 & 71.86 & 86.13 & 70.98 \\  & & 9 & 77.26 & 60.33 & 77.11 & 60.83 \\ \hline \end{tabular} Note: TR and Ev are ecosystem transpiration and soil evaporation, respectively, both in mm d\({}^{-1}\). Here, we emphasize that the ecosystem transpiration was only used to compare the difference in partitioning ET among methods, which cannot represent the absolute value of TR with biophysical significance.  
\end{table} 
Table 2: Solution rates and average daily transpiration, evaporation, and T/ET for each separation method in the fully coupled state. Figure 5: Monthly mean daily variation in transpiration, evapotranspiration, Rg, and VPD in the ecosystem. Note: the gray shadow indicates daytime (08:00–18:00), and the black, red, blue, and green lines in transpiration (TR) and soil evaporation (Ev) correspond to double-layer eddy covariance (DLEC) (methods of Table 1-2.2.2), the conditional eddy covariance (CEC), the modified relaxed eddy accumulation (MREA), and the flux variance similarity (FVS) separation results from eddy covariance, respectively. nomenon is most likely due to the lack of consideration of hyperbolic thresholds [37], which also highlight the importance of independent observation of transpiration and evaporation, but the MREA algorithm is somewhat conservative in its estimation of evaporation fluxes of nonstomatal components when applying flux separation in the sparse forest canopy. As far as each separation method is concerned in describing ecosystem T/ET, unlike the results of vineyards and WRF forests [17], our site did not show similarities between CEC and MREA, but rather the DLEC was consistent with MREA, and the CEC and FVS results were consistent, a point that we believe is mainly due to the plantation canopy. The sparse canopy influences the ratio of transpiration to evapotranspiration allocation, which is more inclined to come from nonstomatal processes (soil evaporation), resulting from a higher degree of stand openness. Among the three methods for separating evapotranspiration components based on the covariance of vorticity above the canopy, the MREA method was found to have the highest correlation with ecosystem evapotranspiration based on double-layer vorticity observations (correlation coefficients of 0.95-0.97, respectively); the CEC method had the highest correlation with ecosystem evapotranspiration based on double-layer vorticity observations (the correlation coefficients were 0.62-0.78); the MREA method had the lowest deviation from ecosystem evapotranspiration based on DLEC (slope 0.92-1.01); the MREA method had the lowest deviation from ecosystem evapotranspiration based on two-layer eddy observations (1:1 slope 0.65-0.95); the FVS method had the lowest RMSE for ecosystem evapotranspiration; the MREA method had the lowest RMSE for ecosystem evapotranspiration RMSE; FVS was the smallest, and for ecosystem evapotranspiration, the MREA was the smallest and CEC was the largest (Table 3). In previous studies of DLEC, since most attention was given to obtaining ecosystem transpiration fluxes, comparisons of transpiration fluxes with process model or Sap flow observations were used to analyze the consistency of the results [9; 12; 22]. We compared the Ev fluxes based on the direct separation of the above-canopy observations, and the FVS and MREA methods met this requirement with correlation coefficients of 0.41-0.78 and RMSEs of 7.5-21.26 w m\({}^{-2}\) within an allowable overall bias of 20%.