Uchytilová, T., Krejza, J.,
Veselá, B., Holub, P.,
Urban, O., Horácek, P.
and Klem, K.
2019
"Ultraviolet radiation modulates
C:N stoichiometry and
biomass allocation in
Fagus sylvatica saplings
cultivated under elevated
CO2 concentration."
Plant Physiology and
Biochemistry 134: 103-112.
NOTE:
Some scientists predict
Earth's stratospheric
ozone layer may experience
further depletion in the future.
There is concern that UV radiation
will increase, potentially causing
damage to some plant species.
Such damage could be offset
by accompanying growth
enhancements due to
atmospheric CO2 enrichment.
This team of seven Czech scientists
investigated these potential outcomes.
SUMMARY:
UV radiation had
little to no impact
on plant biomass.
Elevated CO2
had a positive impact
on the growth of the
European beech seedlings.
It appears that European beech trees
will experience little, if any,
biomass reductions in the future
if UV radiation levels increase.
But, if the air's CO2 content
continues to rise, which it most
likely will, great growth benefits
will ensue via its aerial fertilization
effect, resulting in a large stimulation
of plant biomass above and below ground.
DETAILS:
Uchytilová et al. (2019) say that
ultraviolet (UV) radiation
induces a variety of responses
in plants, including
"DNA modifications
and photorepair,
formation of reactive
oxygen species,
accumulation of
photoprotective compounds
and antioxidants, and
morphological changes."
Uchytilová et al. grew 3-year old
European beech saplings
( Fagus sylvatica )
at a research site in the
Beskydy Mountains of the
Czech Republic under two
atmospheric CO2 concentrations
and one of three UV
radiation treatments
( UV-, UVamb and UV+,
corresponding to UV-B doses
of approximately 0, 10 and
16 kJ m-2 day-1, respectively )
over a two-year period.
CO2 concentrations were set
at either 400 ppm (ambient)
or 700 ppm (elevated),
with the enriched treatment
only being supplied
during the growing season.
Elevated CO2 stimulated
aboveground biomass in the
UV-, UVamb and UV+ treatments
by +27%, +73% and +37%,
respectively, and by
+46%, +56% and +21%
for below ground biomass.
Uchytilová et al. also report
that saplings in the elevated
CO2 treatment
"were also taller and had
greater basal stem diameter."
They noted no statistically significant
interactive effects between
CO2 and UV radiation treatments,
although the positive impact of CO2
on biomass at the highest
UV treatment level was diminished
from that observed at ambient UV levels.
