SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_AvCbranch

Definition: The mean of the change in the branch relative water content (RWC) per unit change in water potential across all measured trees

Description: The mean of the values of hydraulic capacitance for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. Capacitance is the change in % relative water content (i.e., water content relative to its maximum value at saturation) per unit change in water potential. During a severe drought, if capacitance is high, the tree is capable of exploiting its own water reserves to delay desiccation.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_AvCrownHeight

Definition: The mean of the crown lenght across all measured trees

Description: The mean of the values of the crown lenght across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The crown lenght is calculated from the [total height] value subtracted from the [Basal crown height] value. It corresponds to the healthy and functional green crown envelope lenght.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_AvDieback

Definition: The mean of the dieback index across all measured trees

Description: The mean of the values of the dieback index across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The dieback index corresponds to the state of health of the trees determined by assessing foliage loss according to four classes: - `0`: 0% to 25% of defoliation - `1`: 25% to 50% of defoliation - `2`: 50% to 75 % of defoliation - `3`: 75% to 99% of defoliation The value 100% corresponds to a dead tree.

Type: _type_number

Range: -

SPECIES

• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (10)

Key: chr_AvGres

Definition: The mean of the leaf water vapour conductance remaining after stomatal closure across all measured trees

Description: The mean of the values of leaf residual conductance for the apical leaves of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. During a severe drought, following the closure of the stomata, trees continue slowly to lose water. A high residual conductance implies a high sensitivity to severe droughts because it favours desiccation.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_AvHuberValue

Definition: The mean of the ratio of under-bark sapwood cross-sectional area to the leaf area distal to the cross-section in all measured trees

Description: The mean of the Huber values for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The ratio of under-bark sapwood cross-sectional area to the leaf area distal to the cross-section is a measure of allocation of assimilates to build either leaf area for photosynthesis or sapwood (i.e., wood capable of conducting water) to supply the leaves with water. A tree with high Huber values is efficient in providing support to the leaves, but may not invest in high leaf areas. The Huber value is determined on one branch for each of the 10 measufred trees.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_AvP50

Definition: The mean of the water potential at which 50% of the xylem capacity to conduct water to the leaves is lost across all measured trees

Description: The mean of the values of xylem vulnerability to embolism for the apical branches of 10 measured adult dominant/co-dominant trees sampled either inside or in the vicinity of a representative circular plot with a 15 m radius. When a tree is droughted, its xylem is vulnerable to losing its capacity to conduct water to the leaves, i.e., its hydraulic conductivity, because of the formation of air emboli inside the xylem conduits.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (11)
• Pinus sylvestris (14)
• Populus nigra (12)

Key: chr_AvSapWoodAreaTrunk

Definition: The mean of the sapwood area across all measured trees

Description: The mean of the values of the sapwood area across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The sapwood area is based on the measurement of the length of the sapwood estimated from a wood core collected at breast height (1.3 m). This sapwood area is the calculated (in cm2) using the [Trunk circumference].

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_AvSpecLeafArea

Definition: The mean of the ratio of half of the total area of a fresh leaf to its dry mass across all measured trees

Description: The mean of the values of specific leaf area for the apical leaves of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a 15 m radius. Specific leaf area (SLA) is a measure of the return of photosynthetic assimilates via leaf surface display per unit leaf biomiass investment. Leaves with high SLA are said to be acquisitive leaves. They are photosynthetically more productive per unit of mass invested and per unit of time, but they generally have a shorter lifespan, which lowers their cumulative return.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_AvTurgorLossPoint

Definition: The mean of the water potential at which leaves lose turgor across all measured trees

Description: The mean of the values of leaf turgor loss point for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_AvWoodDensity

Definition: The mean of the ratio of dry mass to fresh volume of a branch wood sample across all measured trees

Description: Mean of the values of branch wood density for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. Wood density is a measure of mass invested per unit of volume. High density wood is generally correlated with long wood lifespan, high resistance to pathogen attacks and mechanical damage. It also relates inversely to volumetric growth, hence trees with high wood density are said to be resource conservative.

Type: _type_number

Range: - 0

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (12)
• Populus nigra (11)

Key: chr_LeafAreaIndex

Definition: The projected area of green leaves or needles per unit horizontal ground surface area

Description: The leaf area index value (LAI) is assessed at the position corresponding to and in between 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. Its is assessed using a digital camera (hemispherical pictures). It includes all tree species present in the plot.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (2)
• Pinus sylvestris (4)
• Populus nigra (1)

Key: chr_RootingDepth

Definition: The depth at which the deepest roots can be found

Description: Rooting depth is the depth beyond which there are no roots inside the auger or inside the pit. Rooting depth was generally measured by extracting soil samples down to 1 m depth from five cores taken with a soil auger inside the circular plot with a radius of 15 m, which is representative for the GCU. However, in situations when soil petrosity was very high and using the auger proved impossible, a pit was dug.

Type: _type_number_integer

Range: 100 - 0

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_VarCbranch

Definition: The variance of the change in branch relative water content (RWC) per unit change in water potential across all measured trees

Description: The variance of the values of hydraulic capacitance for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. Capacitance is the change in % relative water content (i.e., water content relative to its maximum value at saturation) per unit change in water potential. During a severe drought, if capacitance is high, the tree is capable of exploiting its own water reserves to delay desiccation.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_VarCrownHeight

Definition: The variance of the crown lenght across all measured trees

Description: The variance of the values of the crown lenght across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The crown lenght is calculated from the [total height] value subtracted from the [Basal crown height] value. It corresponds to the healthy and functional green crown envelope lenght.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_VarDieback

Definition: The variance of the dieback index across all measured trees

Description: The variance of the values of the dieback index across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The dieback index corresponds to the state of health of the trees determined by assessing foliage loss according to four classes: - `0`: 0% to 25% of defoliation - `1`: 25% to 50% of defoliation - `2`: 50% to 75 % of defoliation - `3`: 75% to 99% of defoliation The value 100% corresponds to a dead tree.

Type: _type_number

Range: -

SPECIES

• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (10)

Key: chr_VarGres

Definition: The variance of the leaf water vapour conductance remaining after stomatal closure across all measured trees

Description: The variance of the values of leaf residual conductance for the apical leaves of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. During a severe drought, following the closure of the stomata, trees continue slowly to lose water. A high residual conductance implies a high sensitivity to severe droughts because it favours desiccation.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_VarHtot

Definition: The variance of the vertical tree height across all measured trees

Description: Variance of the values of tree height for 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The tree height corresponds to the total vertical tree height from ground level to the upmost tip.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_VarHuberValue

Definition: The variance of the ratio of under-bark sapwood cross-sectional area to subtended leaf area in a branch across all measured trees

Description: The variance of the Huber values for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The ratio of under-bark sapwood cross-sectional area to the leaf area distal to the cross-section is a measure of allocation of assimilates to build either leaf area for photosynthesis or sapwood (i.e., wood capable of conducting water) to supply the leaves with water. A tree with high Huber values is efficient in providing support to the leaves, but may not invest in high leaf areas. The Huber value is determined on one branch for each of the 10 measufred trees.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (14)
• Populus nigra (15)

Key: chr_VarP50

Definition: The variance of the water potential at which 50% of the xylem capacity to conduct water to the leaves is lost across all measured trees

Description: The variance of the values of xylem vulnerability to embolism for the apical branches of 10 measured adult dominant/co-dominant trees sampled either inside or in the vicinity of a representative circular plot with a 15 m radius. When a tree is droughted, its xylem is vulnerable to losing its capacity to conduct water to the leaves, i.e., its hydraulic conductivity, because of the formation of air emboli inside the xylem conduits.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (11)
• Pinus sylvestris (14)
• Populus nigra (12)

Key: chr_VarSapWoodAreaTrunk

Definition: The variance of the sapwood area across all measured trees

Description: The variance of the values of the sapwood area across 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. The sapwood area is based on the measurement of the length of the sapwood estimated from a wood core collected at breast height (1.3 m). This sapwood area is the calculated (in cm2) using the [Trunk circumference].

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_VarSpecLeafArea

Definition: The variance of the ratio of half of the total area of a fresh leaf to its dry mass across all measured trees

Description: The variance of the values of specific leaf area for the apical leaves of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a 15 m radius. Specific leaf area (SLA) is a measure of the return of photosynthetic assimilates via leaf surface display per unit leaf biomiass investment. Leaves with high SLA are said to be acquisitive leaves. They are photosynthetically more productive per unit of mass invested and per unit of time, but they generally have a shorter lifespan, which lowers their cumulative return.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_VarTurgorLossPoint

Definition: The variance of the water potential at which leaves lose turgor across all measured trees

Description: The variance of the values of leaf turgor loss point for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m.

Type: _type_number

Range: -

SPECIES

• Abies alba (10)
• Pinus pinaster (12)
• Pinus sylvestris (13)
• Populus nigra (15)

Key: chr_VarWoodDensity

Definition: The variance of the ratio of dry mass to fresh volume of a branch wood sample across all measured trees

Description: Variance of the values of branch wood density for the apical branches of 10 measured adult dominant or co-dominant trees sampled either inside or in the vicinity of the representative circular plot with a radius of 15 m. Wood density is a measure of mass invested per unit of volume. High density wood is generally correlated with long wood lifespan, high resistance to pathogen attacks and mechanical damage. It also relates inversely to volumetric growth, hence trees with high wood density are said to be resource conservative.

Type: _type_number

Range: - 0