light availabilities. We also tested differences in response variable
between species within temperature and light regimes to compare
the competitive ability of the species. This was done to be able to
compare the species ability to establish in shallow (50% light) and
deeper (25% light) parts of lakes in temperate (20 ◦C) and subtropical
(30 ◦C) regions, respectively. For this analysis we used one-way
ANOVA and Tukey multiple range tests and checked for variance
homogeneity using Bartlett’s test. Data was log transformed where
necessary. ANOVA analyses were performed in Statgraphics (7.0).
light (Fig. 2). At 30 ◦C E. densa and E. canadensis had the highest
growth rate and L. major’s growth rate was much lower than at 20 ◦C
in both high and low light treatments. Likewise for stem length
where E. canadensis had the highest stem length at both light availabilities
and L. major had a much lower stem length than at 20 ◦C for
both temperatures E. canadensis had a substantially higher number
of branches, lateral spread and branching degree than the other
two species in 50% light. In 25% light the branching was negligible
at both temperatures (Fig. 2).