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:

1. 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)
2. 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)
3. 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)