Data of sap flow, tree size, soil water conditions and meteorology from Finland

Overview
This data set includes the records of stem size at breast height, sap flow, soil water conditions and meteorology of/near two Scots pine (Pinus sylvestris) trees (named 'Pentti' and 'Sylvi') at Hyytiälä, Finland (61.8°N, 24.3°E). The data have been used in Liu et al. Carbon source and sink limitations on boreal trees' cambial growth: implications of a coupled stomatal and growth model (submitted to New Phytologist in October 2023). The Data Collector (Che Liu, University of Helsinki) collected the original data from SmartSMEAR (https://smear.avaa.csc.fi/) and processed to the current format and temporal resolution.
Meanings (and units) of the columns
Sheet "tree_stats" 

DBH, diameter at breast height (cm)
Asw, sapwood area (m^2)
H, tree height (m)
Sheets "Pentti_30min" and "Sylvi_30min"

DOY, day of the year
RBH, change of radius of breast height (mm), measured using the point dendrometer (AX-5 Solartron Metrology) and with thermal expansion corrected. The dendrometers were moved at the beginning of each year.
SFD, sap flow density at breast height (mol H2O m^{-2} sapwood s^{-1}), measured using the thermal dissipation method.
T_air, air temperature (°C)
Precip, rainfall (mm)
RH, relative humidity (%)
VPD, vapour pressure deficit (Pa)
D, VPD converted to mol H2O m^{-3} air using the ideal gas law
PPFD, photosynthetic photon flux density (mol m^{-2} s^{-1}), measured using Li-Cor Li-190SZ quantum sensor over the canopy (35 m high).
T_soil, soil temperature (°C) of the B horizon (10-30 cm deep)
SWC, soil water content (m^3 m^{-3}) of the B horizon (10-30 cm deep), measured using Delta-T ML3.