Establecimiento de cuatro especies de Quercus en el sur de la ...

Capítulo 4
Time to emergence was determined by different variables in each species
(Table 2), but in most cases (3 species) it was related to light availability and to intrinsic
traits related to maternal origin (Fig. 1). Q. ilex was the species with the largest mean
time to emergence, which was only negatively determined by light availability. In Q.
suber however, time to emergence was negatively affected by seed mass, and also
depended on mother tree. No differences were found in mean time to emergence
between deciduous species (Tukey contrasts; z=0.892, P=0.807), which was on average
lower than evergreens. For Q. faginea, the species with the lowest time to emergence,
a complex set of parameters was involved: the interaction term between light
availability and mother tree, the interaction between soil moisture and mother tree,
and a negative effect of seed mass. An interaction between light availability and
mother tree was the only term retained in the model for Q. pyrenaica, the species with
the second lowest average time to emergence. In the case of Q. faginea the interaction
between light and mother tree determined neutral or negative effects of light
availability on time to emergence depending on the mother tree, while for Q.
pyrenaica these effects were positive or negative depending on the mother tree
(Fig.1).
Seedling emergence was highest for Q. suber and Q. pyrenaica (73.5 % and
71.0% respectively; Table 1), and for these species it was determined by the
independent effects of seed mass and mother tree (Table 2). In both cases, seed mass
had a positive influence on seedling emergence (Fig. 2). On the contrary, seed mass
had a different effect on emergence of seedlings from different mother trees in Q.
faginea and Q. ilex, as revealed by a significant interaction between mother and seed
mass (Table 2). In the case of Q. faginea seed mass had a positive influence on
emergence but with different slopes for each maternal plant. On the contrary, for Q.
ilex this relationship was either positive or negative depending on the mother tree (Fig.
2). In addition these two species showed lower rates of emergence (54.2 % and 33.6 %
respectively; Table 1).
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