A reaction–diffusion model of forest boundary with seed dynamics

2015 ◽  
Vol 08 (03) ◽  
pp. 1550033
Author(s):  
J. Rajasingh ◽  
R. Murugesu ◽  
P. Syed Shabudeen
Keyword(s):  
Diffusion Model ◽  
Forest Cover ◽  
Homotopy Perturbation Method ◽  
Reaction Diffusion ◽  
Age Classes ◽  
Homotopy Perturbation ◽  
Reaction Diffusion Model ◽  
Forest Boundary ◽  
Seed Dynamics ◽  
Young Old

The density of forest cover based upon reaction–diffusion model for mono-species of two age classes with seed dynamics is to be attempted. The prevailing densities of young, old species and airborne seedlings are resolved by homotopy perturbation method which is applied in reaction–diffusion model. This model is utilized to verify the effect of the density of forest cover with the following variables namely seed reproduction, seed deposition, seed establishment rates, coefficients of aging of old tree and coefficients of mortality on the space variable.

scholarly journals Dispersal increases the resilience of tropical savanna and forest distributions

2018 ◽  
Author(s):  
Nikunj Goel ◽  
Vishwesha Guttal ◽  
Simon A. Levin ◽  
Carla A. Staver
Keyword(s):  
Global Change ◽  
Diffusion Model ◽  
Equilibrium Position ◽  
Reaction Diffusion ◽  
Tree Cover ◽  
Tropical Savanna ◽  
Spatial Processes ◽  
Reaction Diffusion Model ◽  
Vegetation Feedbacks ◽  
Forest Boundary

AbstractGlobal change may induce changes in savanna and forest distributions, but the dynamics of these changes remain unclear. Classical biome theory suggests that climate is predictive of biome distributions, such that shifts will be continuous and reversible. This view, however, cannot explain a widely observed mismatch between climate and tree cover, which some argue results from fire-vegetation feedbacks maintaining savanna and forest as bistable states, such that, instead, shifts will be discontinuous and irreversible. This bistable model, however, cannot reproduce the spatial aggregation of biomes. Here, we suggest that both models are limited in that they ignore spatial processes, such as dispersal. We examine the contributions of dispersal to determining savanna and forest distributions using a reaction-diffusion model, comparing results qualitatively to empirical savanna and forest distributions in Africa. The diffusion model induces spatially aggregated distributions, separated by a stable savanna-forest boundary. The equilibrium position of that boundary depends not only on precipitation but also on the curvature of precipitation contours with some history dependence (although less than in the bistable model). This model predicts different dynamics in response to global change: the boundary continuously tracks climate, recovering following disturbances, unless remnant biome patches are too small.

scholarly journals A new analyzing technique for nonlinear time fractional Cauchy reaction-diffusion model equations

2020 ◽  
Vol 19 ◽  
pp. 103462 ◽  
Author(s):  
Hijaz Ahmad ◽  
Tufail A. Khan ◽  
Imtiaz Ahmad ◽  
Predrag S. Stanimirović ◽  
Yu-Ming Chu
Keyword(s):  
Diffusion Model ◽  
Reaction Diffusion ◽  
Reaction Diffusion Model ◽  
Model Equations
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