Table 2.
Means (s.d.) for gas exchange characteristics and leaf mass per area (LMA) for leaves grown in exposed (sun) and shaded (shade) regions of the crowns of five canopy tree species
| Species |
Branch light |
N |
Median leaf life span (d) |
N |
Amax (µmol m−2 s−1) |
gs (mol m−2 s−1) |
N |
LMA (g m−2) |
|---|---|---|---|---|---|---|---|---|
| Anacardium excelsum | Sun | 5873 | 250 | 82 | 7·3 (2·8)** | 0·213 (0·098)* | 20 | 111·9 (23·4)*** |
| Shade | 1739 | 186 | 28 | 5·3 (3·6) | 0·164 (0·128) | 20 | 90·7 (13·0) | |
| Luehea seemannii | Sun | 5736 | 158*** | 16 | 10·5 (3·1)* | 0·505 (0·283)** | 25 | 138·1 (28·8)*** |
| Shade | 1448 | 189 | 10 | 8·0 (2·5) | 0·217 (0·069) | 19 | 78·6 (13·1) | |
| Antirrhoea trichantha | Sun | 2764 | 155 | 26 | 10·8 (3·0)*** | 0·412 (0·182)*** | 6 | 65·3 (8·8)*** |
| Shade | – | – | 12 | 5·5 (2·8) | 0·264 (0·192) | 6 | 32·7 (2·9) | |
| Castilla elastica | Sun | 515 | 180 | 13 | 13·7 (2·2)*** | 0·276 (0·083)*** | 13 | 87·2 (6·5)*** |
| Shade | – | – | 16 | 4·5 (1·5) | 0·139 (0·084) | 16 | 32·7 (8·7) | |
| Cecropia longipes | Sun | 699 | 84 | 10 | 25·5 (3·6) | 0·800 (0·345) | 15 | 88·7 (13·2) |
Samples size (N) for gs is the same as that for Amax.
Note that there were no shade leaves for Cecropia.
The median leaf life span (data for shade branches available only for the first two species) is indicated.
Asterisks indicate significant difference between sun and shade branches (*P < 0·05; **P < 0·005; ***P < 0·0005).