## 3 Results
### Drivers of Carbon and Energy Fluxes  
The relationship between the fluxes and meteorological variables across different forest strata for average daily cycles is depicted in Figure 4. A strong dependence of the H, LE, and GPP fluxes on Rg can be observed. The energy fluxes in each stratum display a weak hysteretic character with Rg, although this is not observed in GPP. Due to the minimal contribution of the lower stratum to H, it was excluded from this analysis. The relationships between energy fluxes and atmospheric variables such as Tair and VPD across different strata are depicted in Figure 4c,e, respectively. In these relationships, hysteresis curves are observed. In all cases, the direction of the loops is clockwise, reflecting  
Figure 4: Daily scale relationships between fluxes and atmospheric conditions: H and LE versus (**a**) Rg; (**c**) Tair; (**e**) VPD; (**b**) GPP _versus_ Rg; (**d**) RE _versus_ Tair; (**f**) NEE _versus_ VPD. LE for the ecosystem (LE\({}_{\text{Eco}}\)) and understory (LE\({}_{\text{Under}}\)), H for the ecosystem (H\({}_{\text{Eco}}\)) in W m\({}^{-2}\), and CO\({}_{2}\) components (GPP, RE, and NEE in \(\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{ \text{\text{\text{\text{\text{\text{\text{\text{\text{     }}}}}}}}}}}}}}}\)) for each stratum. The arrows indicate local noon. The circle with the arrow represents the direction hysteresis. Figure 3: Monthly average evaporative fraction for overstory and ecosystem, where sub-index “n” refers to the level of observation of the flux (n = 32, n = 32–11, n = 11). The non-shaded and shaded areas represent the spring–summer (SS) and autumn–winter (AW) periods, respectively. the distinct characteristics between the fluxes and atmospheric conditions throughout the day, which result in a lag between their cycles. Considering the relationship between energy fluxes and atmospheric variables as linear, the angular coefficient in the morning period is lower than in the afternoon period. A similar response occurs around noon; at this point, while the fluxes have already reached their maximum values and are beginning to decrease, the atmospheric variables (Tair and VPD) have not yet peaked. Many studies have shown that the energy and mass fluxes over different types of forests are highly dependent on their LAI and incident solar radiation, making the overstory stratum more representative [14; 21; 23; 24; 25]. Generally, the lower amount of incident solar radiation reaching the forest's interior suppresses some processes in the understory stratum, like GPP [13]. This is evident in Figure 4b, where the overstory GPP displays greater amplitude in daytime values than understory GPP. In both strata, GPP shows a hyperbolic response to solar radiation, as suggested by results obtained in previous studies [45; 54; 55; 56]. However, after reaching its maximum value, the understory GPP remains constant, even with variations in global radiation. This relationship can be explained by the intermittent character of turbulence within the canopy, as described by [PERSON] et al. [31]. This intermittency makes it challenging to accurately describe the daily cycle in this stratum, even in average terms, due storage decoupling between strata. Since CO\({}_{2}\) fluxes are more sensitive to this condition than energy fluxes, this pattern is not observed in energy fluxes [31]. Although the RE in both strata is directly related to air temperature, the response in the understory is more noticeable than in the overstory, suggesting that soil respiration plays a fundamental role in controlling RE within the forest (Figure 4d). Thus, soil temperature may be the most suitable parameter for studying the temperature-response respiration curve for the Understory. [PERSON] et al. [57] suggested conducting a local analysis to determine whether air or soil temperature better characterizes the nocturnal period, as indicated by Equation (3). In this work, soil temperature was not measured.