Elevation modulates the phenotypic responses to light of four co-occurring Pyrenean forest tree species

Data on plant water potential for seedlings of four Pyrenean tree species planted along an elevation gradient. The dataset contains three files:

Biomass.txt: Data on plant biomass per fraction (leaf, stem and roots) 4 years after plantation. Included variables:
- Piso (factor): elevational stage at which the seedling was planted. Two levels: montane (M) or subalpine (S)
- Luz (factor): whether the seedling was plantes at a gap or in the understory. Two levels: gap (O) or understroy (T)
- N (numeric): number of plant in that plot
- Sp (factor): species. Four levels: BEPE (Betula pendula) / PISY (Pinus sylvestris) / PIUN (Pinus uncinata) / ABAL (Abies alba)
- Planta (factor): code to identify uniquely each plant
- File (factor): code to identify uniquely each plant
- GLI (num): Global Light Index, the amount of irradiance that receives each seedling
- Code (factor): code to identify uniquely each plant
- PLB (numeric): total plant biomass (g)
- LFB (numeric): leaf biomass (g)
- STB (numeric): stem biomass (g)
- RTB (numeric): root biomass (g)
- LMF (numeric): leaf mass fraction (LFB/PLB)
- SMF (numeric): stem mass fraction (STB/PLB)
- RMF (numeric): root mass fraction (RTB/PLB)
- SLA (numeric): specific leaf area
- H (numeric): plant height (mm)
- D (numeric): plant diameter at root collar (mm)
- PB2 (numeric): total plant biomass without considering leaves (g)
- SF2 (numeric): stem mass fraction without considering leaves (STB/PB2)
- RF2 (numeric): root mass fraction without considering leaves (RTB/PB2)

init_biomass.txt: for biomass at the moment of plantation
- Piso (factor): elevational stage at which the seedling was planted. Two levels: montane (M) or subalpine (S)
- N (numeric): number of plant
- Sp (factor): species. Four levels: BEPE (Betula pendula) / PISY (Pinus sylvestris) / PIUN (Pinus uncinata) / ABAL (Abies alba)
- Planta (factor): code to identify uniquely each plant
- File (numeric): code to identify uniquely each plant
- PB (numeric): total plant biomass (g)
- LB (numeric): leaf biomass (g)
- SB (numeric): stem biomass (g)
- RB (numeric): root biomass (g)

WaterPot.txt: data on plant water potential for seedlings of four Pyrenean tree species planted along an elevation gradient during a period of intense drought
- Piso (factor): elevational stage at which the seedling was planted. Two levels: montane (M) or subalpine (S)
- Luz (factor): whether the seedling was plantes at a gap or in the understory. Two levels: gap (O) or understroy (T)
- N (numeric): number of plant 
- Parcela (factor): identifier ofthe plot
- Sp (factor): species. Four levels: BEPE (Betula pendula) / PISY (Pinus sylvestris) / PIUN (Pinus uncinata) / ABAL (Abies alba)
- Estacion (factor): the moment for the measurement. One level: September
- GLI (numeric): global light index, the ration of total irradiance received by the plant at the moment of plantation
- WPt (numeric): water potential (bars)