An impulsive modelling framework of fire occurrence in a size structured model of tree-grass interactions for savanna ecosystems
| Autor: | Yatat, V., Couteron, P., Tewa, J. J., Bowong, S., Dumont, Y. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Journal of Mathematical Biology 74 (6) (2017): 1425-1482 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1007/s00285-016-1060-y |
| Popis: | Fires and rainfall are major mechanisms that regulate woody and grassy biomasses in savanna ecosystems. Conditions of long-lasting coexistence of trees and grasses have been mainly studied using continuous-time modelling of tree-grass competition. In these frameworks, fire is a time-continuous forcing while the relationship between woody plant size and fire-sensitivity is not systematically considered. In this paper, we propose a new mathematical framework to model tree-grass interaction that takes into account both the discrete nature of fire occurrence and size-dependent fire sensitivity (via two classes of woody plants). We carry out a qualitative analysis that highlights ecological thresholds and bifurcations parameters that shape the dynamics of the savanna-like systems within the main ecological zones. Moreover, through a qualitative analysis, we show that the impulsive modelling of fire occurrences leads to more diverse behaviors and a more realistic array of solutions than the analogous time-continuous fire models. Numerical simulations are provided to illustrate the theoretical results and to support a discussion about the bifurcation parameters and future developments. Comment: 42 pages, 5 figures |
| Databáze: | arXiv |
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