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Title:
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Effects of UV radiation and rainfall reduction on leaf and soil parameters related to C and N cycles of a Mediterranean shrubland before and after a controlled fire
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Author:
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Díaz-Guerra, Laura; Verdaguer, D.; Gispert, M.; Pardini, G.; González, J. A.; Peruzzi, E.; Masciandaro, G.; Llorens, L.; Font, Joan
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Other authors:
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Universitat de Vic - Universitat Central de Catalunya. Facultat de Ciències i Tecnologia |
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Notes:
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Background and aims In the Mediterranean basin, reduction
in cloudiness owing to climate change is expected
to enhance solar ultraviolet (UV) levels and to
decrease rainfall over the coming years, which would be
accompanied by more frequent and intense wildfires.
The aim of the present study was to investigate the role
of solar UV-A and UV-B radiation in C and N pools of a
Mediterranean shrubland and whether drier conditions
could alter this role before and after a fire.
Methods Over a three-year field experiment, 18 plots of
9 m2 were subjected to three UV conditions (UV-A +
UV-B exclusion, UV-B exclusion or near-ambient
UV-A + UV-B exposure) combined with two rainfall
regimes (natural or reduced rainfall). Several parameters
related to C and N cycles in the soil and in the leaves and
litter of two dominant plant species (Arbutus unedo and
Phillyrea angustifolia) were measured before and after
an experimental fire.
Results UV-A exposure increased soil moisture throughout
the study period, as well as respiration before the fire.
The additional presence of UV-B decreased β-
glucosidase activity at 5–10 cm depth and soil respiration
and pH. UV-B exposure also raised leaf C concentration
in P. angustifolia and δ15N values in A. unedo. Reduced
rainfall often emphasized the opposite effects of UV-A
and UV-B on the studied parameters. After the fire, most
of the UVand rainfall effects were lost.
Conclusion UV-A exposure seems to stimulate soil biological
activity and, thus, C and N turn-over, while the
effect of UV-B would be the opposite. At least in the
short term, the "homogenizing influence" of fire would probably have a stronger effect on the C and N cycles
than the expected changes in UVand rainfall levels. |
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Subject(s):
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-Sequeres
-Matollars -- Mediterrània (Catalunya : Costa)
-Cicle del nitrogen |
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Rights:
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Tots els drets reservats
© Springer (The original publication is available at www.springerlink.com)
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Document type:
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Article
info:eu-repo/publishedVersion |
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Published by:
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Springer
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