Table 2.
Average (±s.e.) and minimum and maximum values of structural and chemical characteristics of different foliage fractions for 122 species of contrasting leaf size and structure (see Appendix for species list)
| Leaf fraction† |
||||
|---|---|---|---|---|
| Characteristic* | Mid-rib | Lamina | Mid-rib + lamina‡ | Petiole§ |
| N percentage (%) | 1·42 ± 0·09 (0·46–5·46) | 2·56 ± 0·10 (1·00–6·59) | 2·37 ± 0·09 (0·96–5·9) | 1·18 ± 0·08 (0·34–4·44) |
| C percentage (%) | 41·00 ± 0·34 (28·6–48·2) | 43·63 ± 0·27 (32·4–49·5) | 43·26 ± 0·27 (31·3–49·1) | 40·05 ± 0·44 (24·9–48·1) |
| Structural C percentage (%) | 40·14 ± 0·33 (25·6–47·8) | 41·80 ± 0·35 (27·3–49·0) | 41·46 ± 0·36 (26·8–48·6) | 39·42 ± 0·44 (23·0–47·0) |
| Fraction of total biomass (g g–1) | 0·129 ± 0·007 (0·012–0·41) | 0·762 ± 0·013 (0·30–0·95) | 0·891 ± 0·011 (0·51–1·0) | 0·109 ± 0·011 (0·0–0·49) |
| Fraction of total leaf N (g g–1) | 0·0796 ± 0·005 (0·0064–0·39) | 0·860 ± 0·009 (0·52–0·99) | 0·940 ± 0·007 (0·63–1·0) | 0·0714 ± 0·008 (0·0–0·38) |
| Fraction of total leaf C (g g–1) | 0·123 ± 0·007 (0·012–0·41) | 0·774 ± 0·013 (0·32–0·98) | 0·897 ± 0·011 (0·49–1·0) | 0·123 ± 0·013 (0·0–0·51) |
| Dry to fresh mass ratio (g g–1) | 0·264 ± 0·012 (0·067–0·60) | 0·284 ± 0·012 (0·066–0·69) | 0·276 ± 0·012 (0·067–0·68) | 0·249 ± 0·014 (0·046–0·60) |
| Density (g cm–3) | 0·461 ± 0·034 (0·078–1·19) | 0·246 ± 0·013 (0·090–0·56) | 0·277 ± 0·013 (0·097–0·60) | 0·361 ± 0·030 (0·024–0·87) |
| Dry mass per unit area (g m–2) | 339 ± 24 (82·7–887) | 53·9 ± 3·2 (12·9–170) | 62·2 ± 3·4 (13·7–197) | 525 ± 35 (45–1700) |
* Structural C percentage (‘protein-fee’ C) was calculated by eqn (1), and eqn (3) provides a sample relationship to calculate the fractions of N and C in different leaf compartments.
† All characteristics are significantly different among different leaf compartments at P < 0·001 according to paired sample t-tests, except for the fractions of total leaf carbon in mid-rib and petiole (P > 0·6) and dry to fresh mass ratios of petiole and mid-rib that differ at P = 0·004.
‡ Mid-rib + lamina characteristics are mass-weighted averages of mid-rib and lamina without mid-rib (see eqn 2 for sample calculations).
§ Average C, N and structural C percentages and dry to fresh mass ratio, density and dry mass per unit area are only calculated for leaves with petioles (33 species did not have petioles; see Appendix).