**3.4. Statistical analysis of data**

Significant differences between means of species and sites were tested with a one-way analysis of variance (ANOVA) and a multiple range test after Scheffé. Differences were considered significant when P ≤ 0.05. Differences between means of measured parameters in the two species at the same site were tested with students t-test at the level of P = 0.05. All statistical analyses were done using Statgraphics 5.0.
