Werner_NFix

Full angiosperm symbiotic N2-fixation database. For full details, please see ReadMe file

Equations of the photosynthesis - stomatal conductance models.

<p>Equations of the photosynthesis - stomatal conductance models.</p

Tests of the coordination hypothesis using experimental values of leaf photosynthetic traits (<i>Vc</i>_max, <i>J</i>_max, <i>J</i>_fac, <i>k</i>₃ and <i>SLA</i>).

<p>A) Relationship between the predicted rates of RuBP carboxylation/oxygenation (<i>W</i>_c) and RuBP regeneration (<i>W</i>_j) under plant growth conditions. B) Relationship between predicted (<i>N</i>_ac) and observed (<i>N</i>_a) leaf N content. <i>N</i>_a was calculated as the sum of the leaf photosynthetic and structural N contents. Leaf photosynthetic N content was predicted using Eqn 2 with the species-specific parameters <i>k</i>₃ and <i>J</i>_fac. C) Relationship between predicted (<i>Np</i>_ac) and observed (<i>Np</i>_a) photosynthetic leaf N content. D) Relationship between predicted and observed leaf C/N ratio. A common leaf structural N content was used (<i>fns</i>  = 0.012 gN g<b>⁻</b>¹ DM). Solid lines are the regressions. Short-dashed and long-dashed lines indicate the confidence (at 95%) and prediction intervals, respectively. The insert in Fig. 1B shows the same relationship without the very high observed <i>N</i>_a values for the PFT1. ***, <i>P</i><0.001.</p

Estimates of the optimized value (for the entire dataset and by PFT) of leaf photosynthetic traits (<i>J</i>_fac, <i>k</i>₃ and <i>SLA</i>).

<p>The squared difference between measured <i>N</i>_a and predicted <i>N</i>_ac values were minimized by Newton’s method. A) The optimization was done with one trait at a time without changing the values of the two other traits. The optimized values are ordered by PFT (i.e. the first value corresponds to PFT1). B) The optimized values by PFT were compared to mean per PFT in the dataset by using a linear regression model. Abbreviations: PFT1, temperate broadleaved and coniferous evergreen trees; PFT2, temperate broadleaved deciduous trees; PFT3, deciduous shrubs and herbs; PFT4, perennial C₃ grasses and forbs; PFT5, C₃ crops (wheat); PFT6, N-fixing trees.</p

Appendix C. Details on the imputation analyses used in this manuscript.

Details on the imputation analyses used in this manuscript

Effects of environmental conditions on the leaf photosynthetic traits: <i>J</i>_max, <i>J</i>_fac, <i>k</i>₃ and <i>SLA</i>.

<p>The factors are environmental growth conditions: radiation (<i>PPFD</i>), temperature (<i>T</i>_g), relative humidity (<i>h</i>_s), air CO₂ concentration (CO₂ level), soil N availability (N level) and soil moisture (H₂O level). A) Degree of freedom (<i>d.f.</i>), variance explained (%), statistical significance and sign (positive or negative) of interactions with continuous variables. B) Coefficients estimate of ANOVA model. All variable values were analyzed at a reference temperature of 20°C. Residuals of analysis followed a normal distribution without transformation for and <i>J</i>_max, and with log-transformation for <i>J</i>_fac and <i>k</i>₃. We only included in the ANOVA model the interactions that were significant.</p

Tests of the coordination hypothesis using values of leaf photosynthetic traits predicted from environmental growth conditions.

<p>A) Relationship between the predicted rates of RuBP carboxylation/oxygenation (<i>W</i>_c) and RuBP regeneration (<i>W</i>_j) under plant growth conditions. B) Relationship between predicted (<i>N</i>_ac) and observed (<i>N</i>_a) leaf N content. The insert in Fig. 2B shows the same relationship without the very high observed <i>N</i>_a values for the PFT1. Symbols are as for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038345#pone-0038345-g001" target="_blank">Fig. 1</a>.</p

Parameters and variables of the photosynthesis - stomatal conductance models.

<p>Parameter values are derived from Wohlfahrt et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038345#pone.0038345-Wohlfahrt1" target="_blank">[3]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038345#pone.0038345-Wohlfahrt2" target="_blank">[4]</a>.</p

Relationships between simulated photosynthetic leaf N content (<i>Np</i>_ac) (A), net photosynthesis (<i>A</i>_n) (B) and photosynthetic N use efficiency (<i>PNUE</i>) (C) and the photosynthetic traits <i>k</i>₃ and <i>J</i>_fac under standard mean environmental conditions (<i>PPFD</i> = 666 µmol m⁻² s⁻¹, <i>T</i>_g = 16.9°C, <i>h</i>_s = 0.74).

<p><i>k</i>₃ is the ratio between and <i>Np</i>_a. <i>J</i>_fac is the ratio between <i>J</i>_max and . A mesh of <i>k</i>₃ values varying between 10 and 300 µmol g⁻¹ N s⁻¹ with 20 steps and of <i>J</i>_fac values varying between 1.75 and 3.5 with 0.05 steps was used. Figures D–E–F, relationships between (<i>Np</i>_ac) (D), net photosynthesis (<i>A</i>_n) (E) and photosynthetic N use efficiency (<i>PNUE</i>) (F) and the radiation (<i>PPFD</i>) and temperature (<i>T</i>_g) conditions during growth. Averages over the dataset of leaf photosynthetic parameters (<i>k</i>₃, <i>J</i>_fac and <i>SLA</i>) are used (<i>k</i>₃ = 59.1 µmol g⁻¹<i>N</i>_pa s⁻¹, <i>J</i>_fac = 2.45, <i>SLA</i>  = 17.7 m² kg⁻¹ DM). The mesh for temperature is 0.5°C between 10 and 30°C and the mesh for radiation is 50 µmol m⁻² s⁻¹ between 300 and 1200 µmol m⁻² s⁻¹. The values of <i>h</i>_s and <i>T</i>_g were fixed at 0.8 and 20°C, respectively. <i>A</i>_n was calculated with the coordinated leaf protein content and <i>PNUE</i> was calculated as the ratio between <i>A</i>_n and <i>Np</i>_ac.</p

Appendix B. Detailed list of all traits considered for this manuscript with detailed references.

Detailed list of all traits considered for this manuscript with detailed references