## 2 Materials and Methods
### Instrumentation and Data Processing
For the flux estimation, the following corrections were applied: double rotation [30], corrections for density effects [31], flux attenuation due to the instrumental setup [32], corrections due to high-pass and low-pass filtering [33; 34], and high-frequency data filtering [35]. To conduct a quality control in the flux data, we used the EddyPro software, which calculates different indicators based on well-developed steady-state and turbulence tests: indicator \"0\" for high-quality fluxes, \"1\" for intermediate-quality fluxes, and \"2\" for low-quality fluxes [36]. We removed fluxes when the indicator was \"2\". Fluxes were discarded in precipitation events and the subsequent half hour (for instrument drying). The physical threshold filter for LE and H were defined by [PERSON] et al. [24] for the same site, being 650 W m\({}^{-2}\) < LE < \(-\)40 W m\({}^{-2}\) and 300 W m\({}^{-2}\) < H < \(-\)60 W m\({}^{-2}\). For the NEE, this filter was considered when \(\mid\)NEE\(\mid\) > 50 \(\mu\)mol m\({}^{-2}\) s\({}^{-1}\). Statistical control was used according to [PERSON] et al. [37]: data outside a standard deviation range of \(\pm\)2.5 of the moving window of 200 data points (separately for daytime and nighttime data) were identified as remaining outliers and removed. The NEE was filtered to remove observations made under low-turbulence conditions based on the \(u_{*}\)-threshold criterion [38]. The footprint of the flux tower was estimated using the model developed by [PERSON] et al. [39] through online data processing (Flux Footprint Prediction; [[http://footprint.klyun.net](http://footprint.klyun.net)]([http://footprint.klyun.net](http://footprint.klyun.net)), accessed on 20 January 2023) and is shown in Figure 1. Because plots within the EC footprint were not always grazed at the same time, different plots had different pasture covers at any given time. The distance at which the contribution to the flux measurements was 90% was approximately 180 m in the predominant wind direction (east). No flux data were discarded by footprint analysis. The raw flux data had 30.8, 29.1, and 18.2% failures for NEE, LE, and H, respectively, due to technical problems in the measurement instruments. After applying all filters and processing quality controls, 57.6, 58.7, and 64.6% remained for the NEE, LE, and H data, respectively. These amounts of failures corroborate the literature on the EC technique [38]. The gaps in NEE, H, and LE flux data were filled using the REddyproc package (Max Planck Institute for Biogeochemistry, Germany) using the marginal distribution sampling method that combines the lookup table and mean diurnal course methods described by [PERSON] et al. [40]. The gap due to the maintenance of the gas analyzer from 15 June to 15 September 2021 was not filled. The NEE was partitioned between gross primary production (GPP) and total ecosystem respiration (Reco) by the nighttime method described by [PERSON] et al. [41] using the REddyproc package. Negative NEE values denote CO\({}_{2}\) assimilation or absorption by the ecosystem, while positive NEE values indicate CO\({}_{2}\) net emissions to the atmosphere.