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Titel |
A mechanistic description of the formation and evolution of vegetation patterns |
VerfasserIn |
R. Foti, J. A. Ramírez |
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 ; 17, no. 1 ; Nr. 17, no. 1 (2013-01-11), S.63-84 |
Datensatznummer |
250017675
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Publikation (Nr.) |
copernicus.org/hess-17-63-2013.pdf |
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Zusammenfassung |
Vegetation patterns are a common and well-defined characteristic of many
landscapes. In this paper we explore some of the physical mechanisms
responsible for the establishment of self-organized, non-random vegetation
patterns that arise at the hillslope scale in many areas of the world,
especially in arid and semi-arid regions. In doing so, we provide a
fundamental mechanistic understanding of the dynamics of vegetation pattern
formation and development. Reciprocal effects of vegetation on the hillslope
thermodynamics, runoff production and run-on infiltration, root density,
surface albedo and soil moisture content are analyzed. In particular, we: (1)
present a physically based mechanistic description of processes leading to
vegetation pattern formation; (2) quantify the relative impact of each
process on pattern formation; and (3) describe the relationships between
vegetation patterns and the climatic, hydraulic and topographic
characteristics of the system. We validate the model by comparing
simulations with observed natural patterns in the areas of Niger near Niamey
and Somalia near Garoowe. Our analyses suggest that the phenomenon of
pattern formation is primarily driven by run-on infiltration and mechanisms
of facilitation/inhibition among adjacent vegetation groups, mediated by
vegetation effects on soil properties and controls on soil moisture and
albedo. Nonetheless, even in presence of those mechanisms, patterns arise
only when the climatic conditions, particularly annual precipitation and net
radiation, are favorable. |
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