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| Titel |
A conceptual dynamic vegetation-soil model for arid and semiarid zones |
| VerfasserIn |
D. I. Quevedo, F. Francés |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 12, no. 5 ; Nr. 12, no. 5 (2008-09-10), S.1175-1187 |
| Datensatznummer |
250010878
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| Publikation (Nr.) |
 copernicus.org/hess-12-1175-2008.pdf |
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| Zusammenfassung |
| Plant ecosystems in arid and semiarid climates show high complexity, since
they depend on water availability to carry out their vital processes. In
these climates, water stress is the main factor controlling vegetation
development and its dynamic evolution.
The available water-soil content results from the water balance in the
system, where the key issues are the soil, the vegetation and the
atmosphere. However, it is the vegetation, which modulates, to a great
extent, the water fluxes and the feedback mechanisms between soil and
atmosphere. Thus, soil moisture content is most relevant for plant growth
maintenance and final water balance assessment.
A conceptual dynamic vegetation-soil model (called HORAS) for arid and
semi-arid zones has been developed. This conceptual model, based on a series
of connected tanks, represents in a way suitable for a Mediterranean
climate, the vegetation response to soil moisture fluctuations and the
actual leaf biomass influence on soil water availability and
evapotranspiration. Two tanks were considered using at each of them the
water balance and the appropriate dynamic equation for all considered
fluxes. The first one corresponds to the interception process, whereas the
second one models the evolution of moisture by the upper soil. The model
parameters were based on soil and vegetation properties, but reduced their
numbers.
Simulations for dominant species, Quercus coccifera L., were carried out to calibrate and
validate the model. Our results show that HORAS succeeded in representing
the vegetation dynamics and, on the one hand, reflects how following a fire
this monoculture stabilizes after 9 years. On the other hand, the model
shows the adaptation of the vegetation to the variability of climatic and
soil conditions, demonstrating that in the presence or shortage of water,
the vegetation regulates its leaf biomass as well as its rate of
transpiration in an attempt to minimize total water stress. |
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