Table II.
Definitions of symbols used in text
| Symbol | Description | Units |
|---|---|---|
| C | Carbon | |
| N | Nitrogen | |
| X | Any element (here, carbon or nitrogen) | |
| A | Molar fraction of 15N or 13C | |
| 〈variable〉 | Denotes 24-h averages | |
| flab, funlab | Fraction of labeled, fraction of nonlabeled | |
| G | Leaf growth zone (cell division, expansion, and maturation zones) | |
| RPT | Recently produced (structurally and functionally differentiated) leaf tissue | |
| LER | Leaf elongation rate | mm d−1 |
| GX, GC, GN | Mass of X, C, or N in the growth zone | μg |
| ρLX, ρLC, ρLN | Lineal density of X, C, or N in recently produced tissue | μg mm−1 |
| IX, IC, IN | Import (net deposition) into the growth zone of X, C, or N | μg d−1 |
| EX, EC, EN | Export (tissue-bound efflux) out of the growth zone of X, C, or N | μg d−1 |
| t | Time | d |
| k10, k12, k21 | First-order rate constants (fluxes I, D, and M, respectively) | d−1 |
| TX, TC, TN | Incorporation of labeled X, C, or N into the system | μg d−1 |
| MX, MC, MN | Incorporation of nonlabeled X, C, or N into the system (one-pool model) | μg d−1 |
| Transfer from Q2 to Q1 of X, C, or N (two-pool model) | ||
| DX, DC, DN | Transfer from Q1 to Q2 of X, C, or N | μg d−1 |
| φ | The relative contribution of MX to IX. Parameter directly fitted in the one-pool model, or equal to k12/(k10 + k12) in the two-pool model | % |
| Q1, Q2 | Compartment sizes (substrate and stores) | μg |
| t0.5 | Half-time | d |
| Q1C:N | Ratio of Q1C to Q1N |