Data from: The functional significance of leaf shape lies in water relations over Thermoregulation: A case study with an arid legume herb
Data files
Jun 03, 2026 version files 377.67 KB
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3-1_230706LeafMorphology.csv
83.95 KB
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3-2_240102PhoData.csv
221.34 KB
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3-3-1_LeafFunctionalTraits240529.csv
27.20 KB
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3-3-2_240126LeafVein20212022.csv
34.20 KB
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README.md
10.97 KB
Abstract
Leaf shape displays remarkable diversity, with its evolution hypothesized to reflect adaptive ecophysiological functions. Theoretical models propose that variation in leaf shape—particularly through modifications in effective leaf width (we)—primarily influences thermoregulation and hydraulic efficiency. However, comprehensive empirical tests of these hypotheses are lacking.
Oxytropis diversifolia E. Peter (Fabaceae) has natural variation in leaf shape (1 leaflet, 1–3 leaflets, and 3 leaflets) and exhibits clinal variation, making it an ideal candidate to test those functional relationships. Here, we quantified leaf morphometrics across populations, logged in situ leaf temperature and gas exchange, and examined leaf anatomy associated with water balance.
We confirmed that the production of more leaflets did reduce we . While leaves with reduced we could stay cooler during the day, the extent of leaf‐to‐air temperature difference was typically small (often within 1°C), suggesting a limited biological impact. Crucially, we identified a key anatomical trade‐off in water relations: reduced we yielded beneficial lower chlorenchyma‐to‐midrib ratios and higher vein density, but at the cost of smaller vascular dimensions. This trade‐off likely underpins the observed, context‐dependent superior gas exchange of the intermediate phenotype.
We propose that the functional significance of leaf shape lies in water relations over thermoregulation, with balancing selection on the anatomical trade‐off providing a plausible mechanism maintaining the polymorphism.
Files and Folders
File: 3-1_230706LeafMorphology.csv
Description: This is the original dataset of Results section 3.1 Leaf Morphometrics.
Variables:
- No: Unique number assigned to each individual (1–1003).
- Species: Species identity of each individual (1 = Oxytropis neimonggolica; 2 = Oxytropis diversifolia; 3 = Oxytropis leptophylla).
- PopID: Population identification number (1–15); 15 populations were sampled in total.
- Pop: Population name; 15 populations were sampled in total.
- IndID: Identification number of each individual within a population, typically ranging from 1–20 or 1–30, as 20–30 individuals were sampled per population.
- Pheno: Leaf phenotype category (T1 = 1 leaflet; T2 = 1–3 leaflets; T3 = 3 leaflets; T5 = 5–13 or more leaflets).
- ID: Unique identifier combining Pop + IndID + Pheno. For example, the first individual (1) with phenotype T1 in population BT is assigned the ID BT1T1.
- Pheno2: Refined phenotype classification incorporating T2 submorphs (T21 = 1-leaflet submorph of T2; T22 = 2-leaflet submorph of T2; T23 = 3-leaflet submorph of T2). Other phenotypes remain unchanged (T1, T3, and T5).
- Leaves: Leaf developmental stage, distinguishing between early and mature leaves for each individual (see Section 2.1, Study System).
- Area: Leaf area (cm²).
- Perm: Leaf perimeter (cm).
- Feret: Leaf length (cm).
- MinFeret: Leaf width (cm).
File: 3-2_240102PhoData.csv
Description: This is the original dataset of Results section 3.2 Field Measurements and Analyses of Leaf Temperature and Gas Exchange (Oxytropis diversifolia only).
Variables:
- No: Unique number assigned to each individual (1–328).
- Year: Year in which the data were collected. Data were collected in two consecutive years: 2021 and 2022.
- Pop: Population name. Four populations were sampled: PE, PSEV, PSIX, and PTWE.
- IndID: Identification number of each individual within a population. Individuals were typically numbered from 1–30 in 2021 and from 40–70 in 2022. Approximately 30 individuals were sampled from each population in each year.
- leaftype: Leaf phenotype category (T1 = 1 leaflet; T2 = 1–3 leaflets; T3 = 3 leaflets).
- ID: Unique identifier combining Pop + IndID + leaftype. For example, the first individual (1) with phenotype T1 in population PE is assigned the ID PE1T1.
- Area: Leaf area (cm²).
- Perm: Leaf perimeter (cm).
- Feret: Leaf length (cm).
- MinFeret: Leaf width (cm).
All the variables from Photo_out onwards : Gas exchange variables which were direct output of the open system infrared gas analyzer (IRGA) (LI‐6400; Li‐Cor, Lincoln, NE, USA). The settings of the system, see article section 2.4 Field Measurements of Leaf Temperature and Gas Exchange. For details of the variables, see the manual of the IRGA system (https://www.licor.com/support/LI-6400/manuals.html).
- Photo_out: Photosynthetic rate (μmol CO₂ m⁻² s⁻¹).
- Cond_out: Conductance to H₂O (mol H₂O m⁻² s⁻¹).
- Ci_out: Intercellular CO₂ concentration (μmol CO₂ mol⁻¹).
- Trmmol_out: Transpiration rate (mmol H₂O m⁻² s⁻¹).
- VpdL_out: Vapor pressure deficit based on leaf temperature (kPa).
- CTleaf_out: Computed leaf temperature (°C).
- Area_in: Leaf area (cm²).
- BLC_1_out: One-sided boundary layer conductance (mol m⁻² s⁻¹).
- StmRat_in: Stomatal ratio estimate.
- BLCond_out: Total boundary layer conductance for the leaf, including stomatal ratio (mol m⁻² s⁻¹).
- Tair_in: Temperature in the sample cell (°C).
- Tleaf_in: Temperature of the leaf thermocouple (°C).
- TBlk_in: Temperature of the cooler block (°C).
- CO2R_in: Reference cell CO₂ concentration (μmol CO₂ mol⁻¹).
- CO2S_in: Sample cell CO₂ concentration (μmol CO₂ mol⁻¹).
- H2OR_in: Reference cell H₂O concentration (mmol H₂O mol⁻¹).
- H2OS_in: Sample cell H₂O concentration (mmol H₂O mol⁻¹).
- RH_R_in: Relative humidity in the reference cell (%).
- RH_S_in: Relative humidity in the sample cell (%).
- Flow_in: Flow rate to the sample cell (μmol s⁻¹).
- PARi_in: In-chamber photosynthetically active radiation (PAR) (μmol m⁻² s⁻¹).
- PARo_in: External photosynthetically active radiation (PAR) (μmol m⁻² s⁻¹).
- Press_in: Atmospheric pressure (kPa).
- CsMch_in: Sample CO₂ offset (μmol CO₂ mol⁻¹).
- HsMch_in: Sample H₂O offset (mmol H₂O mol⁻¹).
- CsMchSD_in: Sample CO₂ offset standard deviation (μmol CO₂ mol⁻¹).
- HsMchSD_in: Sample H₂O offset standard deviation (mmol H₂O mol⁻¹).
- CrMchSD_in: Reference CO₂ offset standard deviation (μmol CO₂ mol⁻¹).
- HrMchSD_in: Reference H₂O offset standard deviation (mmol H₂O mol⁻¹).
- StableF_in: Fraction of stable variables relative to the total number of variables (Stable/Total).
- BLCslope_in: Boundary layer conductance slope (mol m⁻² s⁻¹ cm⁻²).
- BLCoffst_in: Boundary layer conductance offset (mol m⁻² s⁻¹).
- f_parin_in: Fraction of PARi used for energy balance calculations.
- f_parout_in: Fraction of PARo used for energy balance calculations.
- alphaK_in: Parameter used in the conversion of μmol mol⁻¹ to W m⁻².
- Status_in: Instrument status indicators (CO₂, H₂O, pump, flow, CO₂ mixer, fan).
- fda_out: Flow per unit leaf area (mol m⁻² s⁻¹).
- Trans_out: Transpiration rate (mol H₂O m⁻² s⁻¹).
- Tair_K_out: Air temperature in Kelvin (K).
- Twall_K_out: Chamber wall temperature in Kelvin (K).
- R(W/m2)_out: Incoming radiation (W m⁻²).
- Tl-Ta_out: Leaf temperature minus air temperature (energy balance ΔT; °C).
- SVTleaf_out: Saturation vapor pressure at leaf temperature (kPa).
- h2o_i_out: Intercellular H₂O concentration (mmol H₂O mol⁻¹).
- h2odiff_out: Difference between intercellular and sample-cell H₂O concentrations (H₂Oᵢ − H₂OS; mmol H₂O mol⁻¹).
- CTair_out: Air temperature in the leaf chamber (°C).
- SVTair_out: Saturation vapor pressure at air temperature (kPa).
- CndTotal_out: Total conductance (mol H₂O m⁻² s⁻¹).
- vp_kPa_out: Vapor pressure of chamber air (kPa).
- VpdA_out: Vapor pressure deficit based on air temperature (kPa).
- CndCO2_out: Total conductance to CO₂ (μmol CO₂ m⁻² s⁻¹).
- Ci_Pa_out: Intercellular CO₂ pressure (Pa).
- Ci/Ca_out: Ratio of intercellular CO₂ to ambient CO₂ concentration.
- RHsfc_out: Surface humidity (%).
- C2sfc_out: Surface CO₂ concentration (μmol CO₂ mol⁻¹).
- AHs/Cs_out: Ball–Berry parameter (mol m⁻² s⁻¹).
File: 3-3-1_LeafFunctionalTraits240529.csv
Description: This is the original dataset of Results section 3.3 Leaf Anatomy Related With Water Transport Efficiency. Part 1: Anatomical traits derived from leaf cross‐sections.
Variables:
- No: Number assigned to each individual (1–272).
- Pop: Population name; four populations were sampled: PE, PSEV, PSIX, and PTWE.
- Ind: Identification number of each individual within a population. Individuals were typically numbered 1–30 in 2021 and 40–70 in 2022. Approximately 30 individuals were sampled from each population in each year.
- Pheno: Leaf phenotype category (T1 = 1 leaflet; T2 = 1–3 leaflets; T3 = 3 leaflets).
- Pheno2: Refined phenotype classification incorporating T2 submorphs (T21 = 1-leaflet submorph of T2; T22 = 2-leaflet submorph of T2; T23 = 3-leaflet submorph of T2). Other phenotypes remain unchanged (T1 = 1 leaflet; T3 = 3 leaflets).
- Year: Year in which the data were collected (2021 or 2022). Data were collected in two consecutive years.
- IndID: Unique identifier combining Pop + Ind + Pheno. For example, the second individual (2) with phenotype T3 in population PTWE is assigned the ID PTWE2T3. Additional information may be appended to indicate specific leaves and leaflets (e.g., PTWE2T3-1b, where 1 indicates the first leaf and b indicates the second leaflet).
- Leaves: Leaf developmental stage, distinguishing between early and mature leaves for each individual (see Section 2.1, Study System).
- TotalPerim: Total chlorenchyma tissue cross-sectional perimeter (mm).
- TotalArea: Total chlorenchyma tissue cross-sectional area (mm²).
- Thickness: Leaf thickness (mm).
- UpperEpidermis: Adaxial (upper) epidermal thickness (mm).
- LowerEpidermis: Abaxial (lower) epidermal thickness (mm).
- MidveinDiameter: Midrib diameter (mm).
- ConduitDiameter: Vessel diameter (mm).
- MidveinArea: Midrib cross-sectional area (mm²).
- MidveinPerim: Midrib cross-sectional perimeter (mm).
- BSE: Bundle sheath extension cross-sectional area (mm²).
- ConduitNum: Number of vessels in the midrib.
File: 3-3-2_240126LeafVein20212022.csv
Description: This is the original dataset of Results section 3.3 Leaf Anatomy Related With Water Transport Efficiency. Part 2: leaf vein density data derived from leaf skeletons.
- No: the number of each individual, from 1 to 347.
- Pop: The name of each population, 4 populations in total, that is, PE, PSEV, PSIX, PTWE.
- Ind: The ID of each individual in each population. In each population, commonly from 1 to 30 in 2021, from 40 to 70 in 2022. We sampled about 30 individuals in each population of each year.
- Pheno: phenotype of leaves. T1, 1-leaflet; T2, 1-3 leaflets; T3, 3 leaflets.
- Pheno2: incoorperate submorphs of T2 phenotype. T21: 1-leaflet submorph of T2; T22: 2-leaflet submorph of T2; T23: 3-leaflet submorph of T2. Others are the same as "Pheno": T1, 1-leaflet; T3, 3 leaflets. na: not available.
- Year: The year that data were collected, we collected data in two consecutive years, 2021 and 2022.
- IndID: The ID of each individual incoorperating "Pop"+"IndID"+"Pheno". For example, in the "PSIX" population, the first individual "1" with phenotype "T3", given the ID "PSIX1T3". We have additional infomation for each individual, such as "PE52T3-1", 1 means the first leaflet.
- Leaves: discriminate "early" and "mature" leaves for one individual. For details see the article section 2.1 Study system.
- Area: leaf area (mm2).
- Perm: leaf perimeter (mm).
- Feret: leaf length (mm).
- MinFeret: leaf width (mm).
- VTotL: Total vein length (mm).
- Ratio: Perimeter/area ratio
- VeinDensity: Vein density, calculated as VTotL/Area (mm/mm2).