## 2 Materials and Methods
### Ecosystem Flux and Meteorological Measurements  
Net ecosystem CO\({}_{2}\) exchange (NEE) and water (ET) flux measurements in the study sites were estimated with the eddy covariance technique (EC). In brief, the EC system in the ES site was coupled with a three-dimensional sonic anemometer (WindmasterPro, Gill Instruments, Lymington, UK) and an infrared gas analyzer (LI-7500A, LI-COR Biosciences, Lincoln, NE, USA). Data were collected at 10 Hz through an analyzer interface unit (LI-7550, LI-COR Biosciences, Lincoln, NE, USA). On the other hand, meteorological variables measured were relative humidity (RH), air temperature (T\({}_{\text{air}}\)) (HMP45 AC, Vaisala Inc., Helsinki, Finland) and net radiation (Q*; CNR1-L, Kipp and Zonen, Delft, The Netherlands), and precipitation was measured with a tipping bucket rain gauge (TE525-L, Texas Electronic, Dallas, TX, USA).  
The flux measurements in the MS site were performed using a three-dimensional anemometer (CSAT3, Campbell Scientific, Logan, UT, USA) and an open-path gas analyzer (EC150, Campbell Scientific, Logan, UT, USA). Additionally, meteorological variables included a temperature-humidity probe sensor for relative humidity (RH) and air temperature (T\({}_{\text{air}}\)) (CS215-L, Campbell Scientific, Logan, UT, USA), and net radiation was estimated with a four-component radiometer (Q*; CNR4-L, Campbell Scientific Inc., Logan, UT, USA). Precipitation was measured with a tipping bucket rain gauge (TE522 MM, Texas Electronic, Dallas, TX, USA).  
Finally, the EC system for the OG site consisted of a three-dimensional sonic anemometer (Windmaster, Gill Instruments, Lymington, UK) and an infrared gas analyzer (LI-7500A, LI-COR Biosciences, Lincoln, NE, USA). These measurements were made at 10 Hz, storing the data through an analyzer interface unit (LI-7550, LI-COR Biosciences, Lincoln, NE, USA). Ancillary, meteorological variables were collected in parallel. These included a temperature-humidity probe sensor for relative humidity (RH) and air temperature (T\({}_{\text{air}}\)) (HMP45C-L, Vaisala Inc., Helsinki, Finland) and a four-component radiometer to estimate net radiation (Q*; CNR4-L, Kipp and Zonen, Delft, The Netherlands), and precipitation was measured with a tipping bucket rain gauge (TE525-L, Texas Electronic, Dallas, TX, USA).  
At each site, soil volumetric water content was measured with water content reflectometers (CS616, Campbell Scientific Inc., Logan, UT, USA), and soil temperature was estimated with a thermocouple probe (TCAV-L, Campbell Scientific Inc., Logan, UT, USA). All meteorological data in the sites were collected and stored in a data logger and averaged to 30 min intervals, except for precipitation, which was accumulated. A further and detailed description of the main layout for EC instrumentation and measurements can be found in [PERSON] et al. [70].  
Corrections and quality controls of EC data were carried out through a filtering of the friction speed coefficient (u*) for the periods of low turbulence and instrument failure; the data that did not meet these criteria were discarded. Missing data were filled, and then NEE was partitioned into its components of GPP and R\({}_{\text{eco}}\) using the REddyProc based on the procedures described by [PERSON] et al. [71] and [PERSON] et al. [72]. Additional information about the data quality control, flux partitioning and gap-filling is reported in [PERSON] et al. [70].