Chlorophyll fluorescence in Exploratory Region Romania

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This data is Private.

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Dataset Abstract

Productivity is great in forests with a capacity to intercept incoming radiation and harness its energy efficiently. Thus, understanding the relationships between forest diversity, tree canopy biomass and photosynthetic parameters is central to predicting how diversity will affect a key ecosystem function (i.e., productivity). Specific hypotheses to be tested: I) higher tree species diversity enables greater exploitation of light within forest canopies due to niche partitioning, increasing photosynthesis and primary production (NPP); II) photosynthetic acclimation (ecological resilience to changing environmental factors) on singular species may vary according to the varying ecological conditions, but is supposed to be maintained at plot level in mixed population (interaction of different species-specific behaviors). Photosynthetic acclimation was measured with chlorophyll fluorescence (ChlF), by applying fast and reliable techniques based on the fast kinetics of the chlorophyll fluorescence induction in dark adapted leaves. This method is called JIP-test and is based on the measure of the variable fluorescence at different steps of the fluorescence induction. The measurements were carried out in 29 plots of Romania Exploratory Region.

Dataset Design

Chlorophyll fluorescence measurements were replicated on 8 randomly chosen leaves per tree per two level of crown (top and bottom). The measurements were done on the twigs after the dark adaptation (at minumum four hours in black plastic bag, at ambient temperature). In conifers chlorophyll fluorescence measurements took in current year needles (i.e., needles sprouted in 2013, 1-year needles)

Spatial Extent

Râşca, Romania

Taxonomic Extent

4 tree species (total number sampled tree/specie): Abies alba (52), Acer psudoplatanus (43), Fagus sylvatica (62), Picea abies (51)

Data Analysis

Data are treated at tree level (for each tree the data are treated for crown level)

Data columns available in the raw data part of this dataset

ID plot
Romania plot number. Unique number ascribed to each plot
Data group: Exploratory plot id
Values
ROM01
ROM03
ROM02
ROM06
ROM05
Mixture level
Mixture level
Data group: Plot descriptor
Values
3
1
2
4
Species combination
Name of species combined in each mixture. Code used: AA - Abies alba; AP - Acer pseudoplatanus; FS - Fagus sylvatica; PA - Picea abies
Data group: Tree species mix code
Values
AA
AA-AP-FS
AA-FS-AP
AA-AP-FS-PA
AA-FS
Species
Scientific name of the trees sampled for leaf sampling (isotopic analysis, nitrogen analysis, fluorescence measurements, pathogen and insects)
Data group: Tree species
Values
Fagus sylvatica
Picea abies
Acer pseudoplatanus
Abies alba
ID tree
Number of sampled trees for leaf sampling (isotopic analysis, nitrogen analysis, fluorescence measurements, pathogen and insects)
Data group: Tree id
Values
10
13
11
12
1
Top/Bottom
Two levels of crown sampled. Top (T) are the sunny leaves;bottom (B) is the lower part of the crown, in the shade. When T and B were not distinct, the crown level sampled is indicated T+B
Data group: Tree id
Values
T
T+B
B
M0
Approximated initial slope (in ms-1) of the fluorescence transient normalized on the maximal variable fluorescence; Datagroup description: Approximated initial slope of the fluorescence transient
Unit: ms-1
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
0.31495
0.34651250000000006
0.323275
0.33228749999999996
0.3493375
VJ
Variable fluorescence intensity at time 2 millisecond after the onset of the fluorescence induction by saturating light impulse (with intensity > 3000 µmol m-2s-1). It is expressed in arbitrary unit.; Datagroup description: Variable fluorescence at 2 millisecond
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
0.30882499999999996
0.29566250000000005
0.3078125
0.3034125
0.3121875
VI
Variable fluorescence intensity at time 30 millisecond after the onset of the fluorescence induction by saturating light impulse (with intensity > 3000 µmol m-2s-1). It is expressed in arbitrary unit.; Datagroup description: Variable fluorescence at 30 millisecond
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
0.7344249999999999
0.700975
0.7243875000000001
0.7239625000000001
0.6948125
FV/FM
Maximum quantum yield of primary photochemistry in dark-adapted state. Expresses the probability that an absorbed photon will be trapped by the PSII reaction centre; Datagroup description: Maximum quantum yield of primary photochemistry in dark-adapted state
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
0.73495
0.7478875
0.7481625
0.74755
0.72225
Sm
Normalized area above the fluorescence induction curve. It is expressed in arbitrary unit and calculated as SM = Area/ (FM-F0), where F0 is the basl fluorescence intensity, measured at 20 microsecond after the onset of the fluorescence induction by saturating light impulse (with intensity > 3000 µmol m-2s-1).; Datagroup description: Normalized area above the fluorescence induction curve
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
14.288062499999999
12.218312499999998
15.8996625
13.74435
15.2638625
PIabs
Performance index (potential) for energy conservation from photons absorbed by PSII to the reduction of intersystem electron acceptors; Datagroup description: Performance Index (potential) from photons absorbed
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
16.9485625
102.3939
108.5586375
12.5082375
114.82322500000001
PItot
PItot is the performance index for energy conservation from photons absorbed by PSII to the reduction flux of PSI end acceptors. This parameter is calculated from other parameters of the fluorescence induction curve analysis. It is expressed in arbitrary unit.; Datagroup description: Performance Index total
Unit: a.u.
Data group: Fluorescence parameters
Keywords: fluorescence, photosynthetic performance
Values
10.71206469739956
10.17426945718132
10.615196951949597
10.115523166277539
10.515866924784916