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| Titel |
Nonlinear instability and sensitivity of a theoretical grassland ecosystem to finite-amplitude perturbations |
| VerfasserIn |
M. Mu, B. Wang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 14, no. 4 ; Nr. 14, no. 4 (2007-07-19), S.409-423 |
| Datensatznummer |
250012240
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| Publikation (Nr.) |
 copernicus.org/npg-14-409-2007.pdf |
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| Zusammenfassung |
| Within a theoretical model context, the sensitivity and
instability of the grassland ecosystem to finite-amplitude
perturbations are studied. A new approach of conditional nonlinear
optimal perturbations (CNOPs) is adopted to investigate this
nonlinear problem. It is shown that the linearly stable grassland
(desert) states can be nonlinearly unstable with finite-amplitude
initial perturbations, which represent the human activities and
natural factors on the ecosystem. When the moisture index is
between the two bifurcation points, a large enough finite
amplitude perturbation can induce a transition from the grassland
(desert) state to the desert (grassland) state. The thresholds of
such transition along the bifurcation diagram of the moisture
index are also given by the CNOPs approach. The results also
support the viewpoint of Zeng et al., whose emphasis is on the
shading effect of wilted grass on the grassland ecosystem.
Comparisons between the results obtained by approach of CNOPs and
linear singular vectors are made, which demonstrates that CNOPs is
a useful tool to explore the nonlinear features of the ecosystem. |
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