Bogdziewicz, M.,
Fernández-MartÃnez, M.,
Espelta, J.M., Ogaya, R.
and Penuelas, J.
2020
Is forest fecundity
resistant to drought?
Results from
an 18 year
rainfall-reduction
experiment.
New Phytologist
doi: 10.111/nph.16597.
SUMMARY:
Drought
simulation
had no
statistical
impact on
fruit dry mass
production
in any of the
three tree
species.
Year-to-year
variability
and synchrony
of reproduction
were also
not impacted
by drought.
This is good news
for the stability
of these forests,
if they ever
experience the
model-based
predictions of
increasing drought.
Bogdziewicz et al.
say their study results
"indicated substantial
resistance of tree fecundity
in a Q. ilex dominated
forest subjected to
an average 15%
(median 13%)
decrease in the
amount of soil
moisture,"
which findings provide
"growing evidence ...
that Q. ilex dominated forests
are resistant to an increase
in drought to some extent,
suggesting that these
ecosystems may adapt
to a progressive increase
in arid conditions."
DETAILS:
Bogdziewicz et al. (2020) say
"ecosystem services,
such as mitigating the risk
of avalanches, carbon storage,
habitat availability and value
for the economy and recreation,
can suffer if reduced reproduction
slows forest expansion or limits
the recruitment of merchantable
tree species and seed producers t
hat support wildlife."
Five forest researchers
investigated the impact
of artificially-induced drought
on the fecundity of three
dominant tree species.
All growing in the
Prades Mountains
of southern Catalonia
(northeastern Spain).
Since 1999,
an experimental site
was established
in a typical
Holm oak
(Quercus ilex)
forest that was
accompanied
by other
Mediterranean
tree species,
including Mock privet
(Phillyrea latifolia)
and
Strawberry tree
(Arbutus unedo).
A portion of rainwater
was intercepted on
various study plots,
effectively causing
long-term drought
that decreased
soil moisture
by 10-30%
over the
study period.
That allowed
the researchers
to examine the effect
of long-term drought
on the reproduction
of the three tree species.
Figure 1, below:
Fruit production by
(a) Quercus ilex,
(b) Phillyrea latifolia and
(c) Arbutus unedo
in the control and
drought plots.
The solid lines
and shaded areas
are annual means and
associated standard
deviations, respectively.
