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

Whithin population variability influences early seedling establishment on four Mediterranean Oaks
ABSTRACT
Regeneration of Mediterranean forests is severely limited. Multiple abiotic factors,
such as summer drought or light availability, are known to constrain the establishment
of woody seedlings at its first phases, but less attention has been paid to the role of
intraspecific variation in seedling performance. In this study we collected acorns from
different mother trees (as determinants of within population variability) of four
Mediterranean oaks (Q. ilex, Q. suber, Q. faginea and Q. pyrenaica). Acorns were
sowed in field to study their early establishment, from emergence and early growth to
second‐year survival across a gradient of environmental factors. Maternal origin had
an effect on most of the phases studied (time of emergence, percentage of
emergence, establishment success and morphological traits) but main drivers for each
phase were slightly different for each species. In addition to a direct effect, in many
cases intrinsic traits due to maternal origin and seed mass modulated the effects of
environmental conditions on seedling performance. The role of intrinsic factors was
masked under ameliorated conditions (i.e. summer irrigation), indicating the relevant
role of within population variability to cope with the highly heterogeneous and
unpredictable Mediterranean environments. This high variability should be taken into
account in restoration programs.
Keywords:
survival
aboveground biomass, emergence, growth, mother plant, seed, SLA,
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