Table 2.
Trait and ecophysiology values from two wild Protea repens populations in the Western Cape of South Africa. Morphological traits were measured on 20 plants per site, half of which were measured for ecophysiology (two to four leaves per plant) in June–July 2012. Data are raw means and standard deviations. Double asterisks indicate a significant difference between sites at the Bonferroni-adjusted level of P < 0·0038 and a single asterisk is P < 0·05
| Effect | Kleinmond (cooler, moister) |
De Hoop (hotter, drier) |
P-value | ||
|---|---|---|---|---|---|
| Mean | s.d. | Mean | s.d. | ||
| LWR (leaf length·leaf width−1) | 10·99 | 2·05 | 7·92 | 1·38 | <0·0001** |
| Stomatal density (mm−2) | 34·59 | 4·97 | 50·90 | 5·60 | <0·0001** |
| SPI (stomatal density · stomatal pore length2) | 0·14 | 0·03 | 0·11 | 0·02 | <0·0001** |
| SLA (cm2 g−1) | 33·62 | 2·50 | 34·66 | 2·25 | 0·18 |
| Leaf area (cm2) | 6·94 | 1·20 | 4·92 | 0·84 | <0·0001** |
| Stomatal pore length (mm) | 0·064 | 0·008 | 0·046 | 0·002 | <0·0001** |
| Leaf width (mm) | 9·90 | 1·28 | 10·39 | 1·87 | 0·34 |
| Light-saturated photosynthetic rate (µmol CO2 m−2 s−1) | 16·84 | 2·88 | 17·43 | 3·00 | 0·50 |
| Leaf surface temperature (°C) | 16·77 | 2·98 | 18·40 | 2·79 | 0·06 |
| Photosystem II quantum yield | 0·34 | 0·04 | 0·36 | 0·07 | 0·26 |
| Stomatal conductance per unit area (mol H2O m−2 s−1) | 0·224 | 0·051 | 0·206 | 0·063 | 0·30 |
| Transpiration per unit area (mol H2O m−2 s−1) | 3·30 | 0·71 | 3·06 | 0·42 | 0·15 |
| Instantaneous water use efficiency (light-saturated photosynthetic rate · stomatal conductance−1) | 77·30 | 14·45 | 88·54 | 15·52 | 0·014* |