Table I
Species mean values across the whole light gradient for various foliar parameters and the ANCOVA results (F values and significant levels for light, species and their interaction effect, coefficient of determination of the model, and values of the covariant for which means are adjusted): Construction cost (mass based – CC; area based– CCA); concentration of N (mass based – Nm; area based – Na), C and total mineral (TM); and ratio of mass per unit area (LMA). Mean values with the same letter denote not significant differences between species (Scheffé-test, P > 0.05; results of analyses of covariance – one-way ANCOVA –, with the species as the main effect and light as the covariate). F ratio followed by *, ** or *** are significantly higher than unity at 0.05, 0.01 and 0.001 respectively. The covariate variable light was log-transformed.
| Light × | Values of the | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Scheffé-test results | Light | Species | Species | covariant for | ||||||
| Leaf parameter (mean ± SE) |
|
|
R 2 | which means | ||||||
| A. pseudo- | are adjusted | |||||||||
| F. sylvatica | platanus | F. excelsior | F | F | F | ISF(%) | ||||
| CC (g glucose g−1) | 1.44 ± 0.01 a | 1.37 ± 0.01 b | 1.29 ± 0.01 c | 6.2* | 106.8*** | 3.4* | 0.67 | 25.1 | ||
| CCA (g glucose m−2) | 48.11 ± 2.14 a | 65.39 ± 3.22 b | 63.66 ± 3.21 b | 366.1*** | 26.5*** | 8.7*** | 0.79 | 25.1 | ||
| Nm (mg g−1) | 24.1 ± 0.2a | 20.7 ± 0.4 b | 20.6 ± 0.5 b | 9.01 | 16.3* | 5.1 | 0.34 | 25.6 | ||
| Na (g m−2) | 0.81 ± 0.04 a | 1.03 ± 0.04 b | 1.04 ± 0.05 b | 165.7*** | 10.2* | 0.7 | 0.69 | 25.6 | ||
| C (mg g−1) | 479.2 ± 1.3 a | 461.7 ± 2.1 b | 443.4 ± 1.2 c | 15.3* | 29.8*** | 4.5* | 0.78 | 25.2 | ||
| TM (mg g−1) | 31.1 ± 0.5a | 46.5 ± 1.4 b | 59.1 ± 1.3 c | 61.6** | 47.8** | 11.1* | 0.81 | 25.1 | ||
| LMA (g m−2) | 33.84 ± 1.35 a | 47.37 ± 2.27 b | 48.61 ± 2.09 b | 450.4*** | 2.3* | 14.7* | 0.83 | 23.8 | ||