Variable definitions

Gas exchange
Id: Tree-ID
Treat: Treatment code
Obs: Observation number in data series
Photo: Net photosynthesis rate (mol CO2 m-2 s-1)
Cond: Stomatal conductance (mol H2O m-2 s-1)
Ci: Intercellular CO2 concentration (mol CO2 mol air-1)
Trmmol: transpiration (mmol m-2 s-1)
VpdL: Leaf-to-air vapor pressure difference (kPa)
CTleaf: Leaf temperature calculated from energy balance (C)
Area: Projected area of the measured needles (cm2)
Tair: Air temperature inside measurement chamber (C)
CO2R: Reference CO2 concentration (mol CO2 mol air-1)
CO2S: Sample CO2 concentration (mol CO2 mol air-1)
CO2Scorr: Sample CO2 concentration (mol CO2 mol air-1)  CO2 concentration corrected for diffusion leaks according to Li-6400 instrument manual (only for data used in fitting A-Ci curves)
H2OR: Reference H2O concentration (mmol H2O mol air-1)
H2OS: Sample H2O concentration (mmol H2O mol air-1)
RH_R: Reference air relative humidity (%)
RH_S: Sample air relative humidity (%)
Flow: Flow rate (mol s-1)
PARi: Photosynthetically active radiation inside measurement chamber (mol m-2 s-1)
Press: atmospheric pressure kPa


Needle properties
Id: Tree-ID
Treat: Treatment code
Origin: Tree origin (high or low latitude)
Needle area: Projected needle area (mm2)
Dry weight: Total needle dry weight (g)
LMA: leaf mass per area (g m-2)
Narea: Area-based needle nitrogen content (g N m-2 needle)
Nmass: Mass-based needle nitrogen content (%) 


Height growth and bud development
Id: Tree-ID
Treat: Treatment code
Start height: Cutting height at the start of the experiment (cm)
End height: Cutting height at the end of the experiment (cm)
DX: Bud development stage on day X after the start of the day length and temperature treatments  classification was based on changes in bud scales as in Slaney et al. 2007 https://doi.org/10.1093/treephys/27.2.301)

