|
Titel |
Nonlinearly combined impacts of initial perturbation from human activities and parameter perturbation from climate change on the grassland ecosystem |
VerfasserIn |
G. Sun, M. Mu |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1023-5809
|
Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 18, no. 6 ; Nr. 18, no. 6 (2011-11-29), S.883-893 |
Datensatznummer |
250014001
|
Publikation (Nr.) |
copernicus.org/npg-18-883-2011.pdf |
|
|
|
Zusammenfassung |
Human activities and climate change are important
factors that affect grassland ecosystems. A new optimization approach,
the approach of conditional nonlinear optimal perturbation (CNOP)
related to initial and parameter perturbations, is employed to
explore the nonlinearly combined impacts of human activities and
climate change on a grassland ecosystem using a theoretical
grassland model. In our study, it is assumed that the
initial perturbations and parameter perturbations are regarded as
human activities and climate change, respectively. Numerical results
indicate that the climate changes causing the maximum effect in
the grassland ecosystem are different under disparate intensities of
human activities. This implies the pattern of climate change is very
critical to the maintenance or degradation of grassland ecosystem in
light of high intensity of human activities and that the grassland
ecosystem should be rationally managed when the moisture index
decreases. The grassland ecosystem influenced by the nonlinear
combination of human activities and climate change undergoes abrupt
change, while the grassland ecosystem affected by other types of human
activities and climate change fails to show the abrupt change under a
certain range of perturbations with the theoretical model. The
further numerical analyses also indicate that the growth of living
biomass and the evaporation from soil surface shaded by the wilted
biomass may be crucial factors contributing to the abrupt change of the grassland
equilibrium state within the theoretical model. |
|
|
Teil von |
|
|
|
|
|
|