Em50 data logger

The experiment was carried out for 60 days under greenhouse conditions (25/21 °C; 50/60% relative humidity, 14/10 h day/night photoperiod) at the greenhouses of the Universidad de La Frontera, Temuco, Chile. The watering regimes were applied 5 days post-transplantation via irrigation with the respective amount of tap water. Soil water content in the substrate of pots was measured in situ using GS3 sensors and EM 50 data loggers (Decagon^® Devices, Pullman, WA, USA).

MPS-2 sensors and EM-50 data loggers (Decagon Devices, United States) for continuously recording soil temperature and soil water potential (Ψ_soil) were installed at each study site in spring 2014. Two to three MPS-2 sensors per soil depth were embedded in the front wall of the soil pit at 20, 80, and 140 cm depth (at 180–200 cm depth only in Chamoson and Saillon). Measurements of Ψ_soil were temperature corrected to 22°C according to Walthert and Schleppi (2018) (link). Soil temperature and soil water potential (Ψ_soil) have been recorded from spring 2014 onward in hourly intervals. In order to characterize the forest sites, daily data from year 2015 were calculated and divided into four annual quarters (January–March, April–June, July–September, October–December).

The meteorological factors, solar radiation (R_s, W m⁻²), relative humidity (RH, %), air temperature (T_a, °C), and vapor pressure deficit (VPD, kPa), for field and greenhouse experiments are shown in Figure 1. In the field experiment of 2016, meteorological data were recorded every 15 min from a weather station (Weather Hawk, Campbell Scientific, USA) 50 m away from the experiment field. In the greenhouse experiment of 2017, an automatic weather station (HOBO, Onset Computer Corp., USA) was installed in the middle of the greenhouse and data were collected every 15 min. VPD was calculated from RH and T_a (Norman, 1998 ). To measure soil water content (SWC, cm³ cm⁻³), one 5TE sensor (Decagon Devices, Inc., USA) was installed at the depth of 15 cm in three randomly selected containers in each treatment in both experiments. The data were collected every 30 min by an EM50 data logger (Decagon Devices, Inc., USA). Sensors were calibrated by optimizing gravimetrically and sensor-measured volumetric water contents.

Measurements were taken on 21 paramo species from the Parque Ecológico Matarredonda (4°33’38.1” N and 74°0’7.3” W) located in the oriental range of the Colombian Andes. Elevation at this park ranges from 3,100 to 3,600 m.a.s.l. The mean annual temperature (MAT) at the study site is 8.8°C [26 (link)]; mean annual precipitation is 1,178 mm and the mean relative humidity is 88% [45 (link)]. To better describe the actual climate experienced by plants (microclimate) at the study site, we recorded air temperature at 30 cm above the soil surface every 30 minutes from December 2017 to December 2018 using an automatic recording system consisting of an EM-50 data logger (Decagon Devices, Inc., Pullman, WA) connected to a VP-4 humidity and temperature sensor with a radiation shield installed (Decagon Devices, Inc., Pullman, WA).

All the experiments were performed in September 2015 on 2 year old vines. Six plants were pruned as a single-cordon and grafted onto SO4 (V. berlandieri $\times$
V. riparia) rootstock. Vitis vinifera L. (cv “Colorino”) were used for the trials. The plants were arranged to 2 L pots filled with a peat:sand mix (2:1). The vines were acclimated to the same environmental condition (24 °C; $45.5\%$ of relative humidity; approximately $660\mathrm{\mu }\text{mol}{\text{m}}^{-2}{\text{s}}^{-1}$ P.A.R.) inside the laboratory of the Department of physics at the University of Pisa, Italy. The measurements were performed under the same environmental conditions. Photon Flux measurements were conducted using em50 data logger (Decagon Devices, Inc.) equipped with a calibrated QSO-S PAR Photon Flux sensor. The environmental conditions, temperature and humidity, were measured with a calibrated usb temperature and humidity data logger (model IMD 100, Imagintronix Inc.). During the experiments, the photoperiod was 13 h 15 min day and 10 h 45 min night. For each of six plants all leaves fully extended and developed were sampled from the main shoot and, according to Kapos [29 (link)], the water content of leaves was determined by weighing the leaves immediately after sampling, drying at 105 °C, and reweighing 24 h later.