Vegetative
Soil warming significantly increased early vegetative growth for some
germination strategies (Table 1). Soil warming significantly increased
the number of leaves and the leaf increment (leaf number per day) in the
immediate and postponed-deep germination strategies, but not the
staggered or postponed strategy (Fig. 2a and b). Leaf size decreased
under warmer conditions only in the immediate germination strategy,
while for other strategies leaf number between ambient and warmer soil
was constant. SLA differed across strategies and warming increased SLA
regardless of the germination strategies (Table 1).
The effect of warming and germination strategies on vegetative growth
diminished at the transition from vegetative to reproductive stage when
many individuals had just started to flower. Rosette size indicated by
the canopy area and leaf number were not affected by warming and
germination strategy (Table 1). Interestingly, at the transition to
reproductive stage, warming was associated with a reduction instead of
an increase in leaf increment regardless of germination strategy –
contrary to the response shown during the early vegetative state (Fig.
2, Table 1). Thereby, despite the positive effect of warming on
vegetative at the early stage, final aboveground biomass of plants
growing under warming treatment was significantly lower than that of
ambient plants (Fig. 1, Table 1).