## 2 Materials and Methods
### Instrumentation and Data Processing  
A flux tower was installed between the rotational plots at 53\({}^{\circ}\)45\({}^{\prime}\)36.097\({}^{\prime\prime}\) W and 29\({}^{\circ}\)43\({}^{\prime}\)27.502\({}^{\prime\prime}\) S, 88 m above sea level (Figure 1). The evaluation period of the flux tower data was from 1 January 2015 to 31 December 2021. The high frequency (10 Hz) sensor array, installed 3 m above ground, included a 3D sonic anemometer (Wind Master Pro; Gill Instruments, Hampshire, UK) to measure wind components and air temperature and an open-path gas analyzer (LT500, LI-COR Inc., Lincoln, NE, USA) to determine CO\({}_{2}\)/H\({}_{2}\)O concentrations until 15 June 2016. Afterward, the gas analyzer and anemometer were replaced with the integrated open-path CO\({}_{2}\)/H\({}_{2}\)O gas analyzer and 3D sonic anemometer (IRGASON, Campbell Scientific Inc., Logan, UT, USA). No data were collected from 15 June to 15 September 2021 due to technical problems. Low frequency (1 Hz) atmospheric variables were measured with the following sensors placed at a 3 m height: air temperature (T\({}_{\mathrm{a}}\), \({}^{\circ}\)C) and relative humidity (RH, %) with a thermo-hygrometer (HMP155, Vaisala, Finland) until 15 June 2016, and then with a new thermo-hygrometer (CS215-L, Campbell Scientific Inc., Logan, UT, USA), incoming shortwave radiation (R\({}_{\mathrm{g}}\), W m\({}^{-2}\)) and net radiation (R\({}_{\mathrm{n}}\), W m\({}^{-2}\)) calculated from incoming longwave, outcoming longwave, incoming shortwave, and outcoming shortwave solar radiation, collected with a net radiometer (CNR4, Kipp & Zonen, Delft, the Netherlands). Precipitation (Prec, mm) was measured by a rain gauge (TR525 USW, Texas Electronics, Dallas, TX, USA) at a 1.7 m height. Soil heat flux (G, Wm\({}^{-2}\)) was measured with soil heat plates (HFP01, Hukseflux Thermal Sensors BV, Delft, the Netherlands) placed at a 0.10 m depth. Soil temperature (T\({}_{\mathrm{s}}\), \({}^{\circ}\)C) was evaluated with a temperature probe (T108, Campbell Scientific Inc., Logan, UT, USA) at a depth of 0.05 m. Soil water content (SWC, m\({}^{3}\) m\({}^{-3}\)) was measured using a water content reflectometer (CS616, Campbell Scientific Inc., Logan, UT, USA) at a depth of 0.10 m. The data collection system was initially set up with a CR1000 datalogger (CR1000, Campbell Scientific Inc., Logan, UT, USA) to collect the high- and low-frequency data. After 5 December 2019, the atmospheric high- and low-frequency data were collected with a CR6 datalogger (CR6, Campbell Scientific Inc., Logan, UT, USA) and the soil data by a CR1000. The low-frequency data were grouped into 30 min averages. From November 2019 through March 2020, no data were collected from the soil sensors. There were occasional power outages or malfunctioning sensors, which caused failures in data collection and generated gaps. To complete the missing data for the meteorological variables of air temperature (18.9% gaps), relative humidity (18.8% gaps), and solar radiation (10.4% gaps), we utilized data from the official INMET weather station (National Institute of Meteorology; code OMM 86977), which is 3.7 km from the flux tower (29.72\({}^{\circ}\) W, 53.72\({}^{\circ}\) S, 103 m above sea level). The remaining gaps of 1.2, 4.1, and 2.7% for air temperature, solar radiation, and relative humidity, respectively, were filled using reanalysis data obtained from ERA5 hourly data on pressure levels from 1979 to the present CopernicusClimate Change Service (C3S) Climate Data Store (CDS) [29]. The precipitation and soil moisture data were compared with the data from the INMET station to identify and close possible gaps. The INMET station database was also used to obtain climatological data (30-year average, 1981-2010). High-frequency data processing was performed using the eddy covariance (EC) technique with EddyPro software (version 7.0.9; LI-COR Inc., Lincoln, NE, USA) to estimate NEE (CO\({}_{2}\) net exchange ecosystem), latent heat flux (LE), and sensitive heat flux (H) in a half-hourly frequency.