Lotka Volterra Competition Diffusion System Research Articles

Global dynamics of a Lotka-Volterra competition-diffusion system with advection and nonlinear boundary conditions

Global dynamics of a Lotka-Volterra competition-diffusion system with advection and nonlinear boundary conditions

Coexistence and competitive exclusion in a time-periodic Lotka-Volterra competition-diffusion system

The evolutionary impact of both temporal periodicity and spatial heterogeneity on population ecology is a challenging problem. Hutson et al. (2001) [12] and Bai et al. (2022) [2] studied the effects of diffusion rates on the dynamics of a time-periodic Lotka-Volterra competition-diffusion system with identical interspecific competition abilities. In this paper, we consider the case of different interspecific competition coefficients. The obtained results can be divided into two groups. The first part focuses on the interplay between the diffusion intensities and the interspecific competition coefficients on the dynamics in the weak competition case. We provide some sufficient conditions on coexistence and competitive exclusion. The second part considers the dynamics for fixed diffusion coefficients and varying competition coefficients. We not only provide a complete classification on the dynamics when one of the interspecific competition coefficients is small, but also show the multiple coexistence periodic patterns by applying the bifurcation method.

Sharp estimates for the spreading speeds of the Lotka-Volterra competition-diffusion system: The strong-weak type with pushed front

We consider the classical two-species Lotka-Volterra competition-diffusion system in the strong-weak competition case. When the corresponding minimal speed of the traveling waves is nonlinearly selected, we show that the solution of the Cauchy problem uniformly converges to the minimal traveling wave in two different situations, for which the invading speed is locally determined: (i) one species is an invasive one and the other is a native species; (ii) both two species are invasive species.

Lotka–Volterra competition-diffusion system: the critical competition case

We consider the reaction-diffusion competition system in the so-called critical competition case. The associated ODE system then admits infinitely many equilibria, which makes the analysis intricate. We first prove the nonexistence of ultimately monotone traveling waves by applying the phase plane analysis. Next, we study the large time behavior of the solution of the Cauchy problem with a compactly supported initial datum. We not only reveal that the “faster” species excludes the “slower” one (with a known spreading speed), but also provide a sharp description of the profile of the solution, thus shedding light on a new bump phenomenon.

Global dynamics of a Lotka-Volterra competition-diffusion system with nonlinear boundary conditions

In this paper, a Lotka-Volterra competition-diffusion system subject to nonlinear boundary conditions is considered with an aim to understand the nonlinear balance between two competing nonlinear mechanisms (namely, interior reaction and boundary flux). A complete picture on the global dynamics (including the existence, nonexistence, global stability, and steady-state bifurcation of semi-trivial positive steady-state solutions) has been studied in terms of inter-specific competition coefficients, the growth rate functions, and boundary reaction functions. Our results extend largely the relevant results in the existing literature on Lotka-Volterra competition-diffusion systems, even those with homogeneous boundary conditions.

Front propagation and blocking for the competition-diffusion system in a domain of half-lines with a junction

<p style='text-indent:20px;'>The two-component Lotka-Volterra competition-diffusion system is well accepted as a model describing the invasion of a superior species into a new habitat. Under a bistable condition, we deal with the system in a domain of half-lines with a single junction and investigate the condition for the invasion from some of the half-lines beyond the junction or blocking the propagation of the superior species. We first give a sufficient condition for the invasion in the whole domain by a subsolution. Then, making use of sub- and supersolutions, we construct a standing front solution blocking the propagation if the number of half-lines occupied by the inferior species is sufficiently larger than that occupied by the superior species.</p>

Propagating direction in the two species Lotka-Volterra competition-diffusion system

The sign of the traveling wave speed in the two species Lotka-Volterra competition-diffusion system under strong competition provides important information about the competitive advantage of the species. To study the sign problem, we propose a mini-max characterization of the coefficients in the reaction terms when the wave speed is zero. Applying our characterization, some explicit conditions under which the speed sign can be determined are obtained.

Dynamics of a periodic-parabolic Lotka–Volterra competition-diffusion system in heterogeneous environments

The effects of spatial heterogeneity on the dynamics of reaction-diffusion models have been studied extensively. In particular, global dynamics of general spatially heterogeneous (but temporally static) Lotka–Volterra competition-diffusion systems were completely clarified by He and Ni in 2016. However, the evolutionary impacts of temporal periodicity combined with spatial heterogeneity in population ecology remain a challenging issue. In this work, we consider a population model of two competing species in a both spatially varying and temporally periodic environment, where the two species only differ in their random dispersal rates but are otherwise ecologically identical. In a pioneering 2001 work on this model by Hutson et al., by constructing various choices of resource functions and dispersal rates of the two species, the authors demonstrated that all the following three types of dynamics are possible: (i) stable coexistence of the two species; (ii) the slower diffuser invades the faster one but not vice versa; (iii) the faster diffuser invades the slower one but not vice versa. This is in drastic contrast with the spatially heterogeneous but temporally static case, where Dockery et al. showed in 1998 that the slower diffuser always wipes out the faster one. In this paper, we completely and explicitly characterize the asymptotic stability of both semitrivial periodic solutions in terms of the two dispersal rates and the resource function, when either dispersal rate is sufficiently small or large. In particular, the direction of selection on the dispersal rate during the evolution can be elucidated in these instances. Some novel analytical methods are developed to investigate asymptotic behaviors of the underlying time-periodic parabolic eigenvalue problem and its adjoint problem. We hope that these methods are of independent interest in the area of time-periodic parabolic equations.

Asymptotic analysis of the bistable Lotka-Volterra competition-diffusion system

We study traveling wave solutions of the Lotka-Volterra competition-diffusion system for two species with bistable nonlinearity. We analyze the speed of propagation and, most importantly, the sign of the speed, which determines the winner of the competition, in several limiting cases. One we refer to as the strong competition. Here the inter-species competition for each species is much stronger than the intra-species competition. Another is a moderate competition, where the inter- and intra-species competitions are close to each other in strength. We also analyze the cases of fast and slow competitors, i.e., when the diffusion coefficient of one of the species is much larger (or much smaller) than the other. We employ asymptotic and perturbation methods and support our approximate results by direct numerical integration.

Existence of Front–Back-Pulse Solutions of a Three-Species Lotka–Volterra Competition–Diffusion System

Existence of Front–Back-Pulse Solutions of a Three-Species Lotka–Volterra Competition–Diffusion System

Asymptotic spreading of interacting species with multiple fronts II: Exponentially decaying initial data

This is part two of our study on the spreading properties of the Lotka-Volterra competition-diffusion systems with a stable coexistence state. We focus on the case when the initial data are exponential decaying. By establishing a comparison principle for Hamilton-Jacobi equations, we are able to apply the Hamilton-Jacobi approach for Fisher-KPP equation due to Freidlin, Evans and Souganidis. As a result, the exact formulas of spreading speeds and their dependence on initial data are derived. Our results indicate that sometimes the spreading speed of the slower species is nonlocally determined. Connections of our results with the traveling profile due to Tang and Fife, as well as the more recent spreading result of Girardin and Lam, will be discussed.

Entire solutions of time periodic bistable Lotka–Volterra competition-diffusion systems in $${\mathbb {R}}^N$$

This paper is concerned with entire solutions of a two species time periodic bistable Lotka–Volterra competition-diffusion systems in $${\mathbb {R}}^N$$ . Here an entire solution refers to a solution that is defined for all time and in the whole space. It is known that “annihilating-front” type entire solutions have been obtained recently in $${\mathbb {R}}$$ . In the present paper, we first prove that there is a new type of entire solution which behaves as three time periodic moving planar traveling fronts as time goes to $$-\infty $$ and as a time periodic V-shaped traveling front as time goes to $$+\infty $$ in $${\mathbb {R}}^N$$ . Furthermore, we show that the propagating speed of such entire solutions coincides with the unique speed of the time periodic planar front, regardless of the shape of the level sets of the fronts.

On the effects of carrying capacity and intrinsic growth rate on single and multiple species in spatially heterogeneous environments.

We first consider a diffusive logistic model of a single species in a heterogeneous environment, with two parameters, r(x) for intrinsic growth rate and K(x) for carrying capacity. When r(x) and K(x) are proportional, i.e., [Formula: see text], it is proved by Lou (J Differ Equ 223(2):400-426, 2006) that a population diffusing at any rate will reach a higher total equilibrium biomass than the population in an environment in which the same total resources are distributed homogeneously. This paper studies another case when r(x) is a constant, i.e., independent of K(x). In such case, a striking result is that for any dispersal rate, the logistic equation with spatially heterogeneous resources will always support a total population strictly smaller than the total carrying capacity at equilibrium, which is just opposite to the case [Formula: see text]. These two cases of single species models also lead to two different forms of Lotka-Volterra competition-diffusion systems. We then examine the consequences of the aforementioned difference on the two forms of competition systems. We find that the outcome of the competition in terms of the dispersal rates and spatial distributions of resources for the two forms of competition systems are again quite different. Our results indicate that in heterogeneous environments, the correlation between r(x) and K(x) has more profound impacts in population ecology than we had previously expected, at least from a mathematical point of view.

Global directed dynamics of a Lotka–Volterra competition-diffusion system

In this study, we consider a directed–diffusion system describing the interactions between two organisms in heterogeneous environment. We first establish a linearly stability of the co-existence (positive) steady state. Then we further present a classification on all possible long-time dynamical behaviors by appealing to the theory of monotone dynamical systems.

Global Dynamics of a Lotka–Volterra Competition Diffusion System with Nonlocal Effects

This paper is concerned with the global dynamics of a Lotka–Volterra competition diffusion system having nonlocal intraspecies terms. Based on the reconstructed comparison principle and monotone iteration, the existence and uniqueness of the solution for the corresponding Cauchy problem are established. In addition, the spreading speed of the system with compactly supported initial data is considered, which admits uniform upper and lower bounds. Finally, some sufficient conditions for guaranteeing the existence and nonexistence of Turing bifurcation are given, which depend on the intensity of nonlocality. Comparing with the classical Lotka–Volterra competition diffusion system, our results indicate that a nonconstant periodic solution may exist if the nonlocality is strong enough, which are also illustrated numerically.

The effect of initial values on extinction or persistence in degenerate diffusion competition systems.

When the asymptotic spreading for classical monostable Lotka-Volterra competition diffusion systems is concerned, extinction or persistence of the two competitive species is completely determined by the dynamics of the corresponding kinetic systems, while the size of initial values does not affect the final states. The purpose of this paper is to demonstrate the rich dynamics induced by the initial values in a class of degenerate competition diffusion systems with weak Allee effect. We present various extinction or persistence results by selecting different initial values although the corresponding kinetic system is fixed, which also implies the existence of balance between degenerate nonlinear reaction and diffusion. For example, even if the positive steady state of the corresponding kinetic system is globally asymptotically stable, we observe four different spreading-vanishing phenomena by selecting different initial values. In addition, the interspecific competition of one species may be harmful to the persistence of the other species by taking proper initial values. Our results show that the superior competitor in the sense of the corresponding kinetic system is not always unbeatable, it can be wiped out by the inferior competitor in the sense of the corresponding kinetic system depending on the size of initial habitats as well as the intensity of Allee effect.

Global dynamics of a general Lotka-Volterra competition-diffusion system in heterogeneous environments

Previously in [ 14 ], we considered a diffusive logistic equation with two parameters, \begin{document}$ r(x) $\end{document} – intrinsic growth rate and \begin{document}$ K(x) $\end{document} – carrying capacity. We investigated and compared two special cases of the way in which \begin{document}$ r(x) $\end{document} and \begin{document}$ K(x) $\end{document} are related for both the logistic equations and the corresponding Lotka-Volterra competition-diffusion systems. In this paper, we continue to study the Lotka-Volterra competition-diffusion system with general intrinsic growth rates and carrying capacities for two competing species in heterogeneous environments. We establish the main result that determines the global dynamics of the system under a general criterion. Furthermore, when the ratios of the intrinsic growth rate to the carrying capacity for each species are proportional — such ratios can also be interpreted as the competition coefficients — this criterion reduces to what we obtained in [ 18 ]. We also study the detailed dynamics in terms of dispersal rates for such general case. On the other hand, when the two ratios are not proportional, our results in [ 14 ] show that the criterion in [ 18 ] cannot be fully recovered as counterexamples exist. This indicates the importance and subtleties of the roles of heterogeneous competition coefficients in the dynamics of the Lotka-Volterra competition-diffusion systems. Our results apply to competition-diffusion-advection systems as well. (See Corollary 5.1 in the last section.)

Asymptotic spreading of interacting species with multiple fronts Ⅰ: A geometric optics approach

We establish spreading properties of the Lotka-Volterra competition-diffusion system. When the initial data vanish on a right half-line, we derive the exact spreading speeds and prove the convergence to homogeneous equilibrium states between successive invasion fronts. Our method is inspired by the geometric optics approach for Fisher-KPP equation due to Freidlin, Evans and Souganidis. Our main result settles an open question raised by Shigesada et al. in 1997, and shows that one of the species spreads to the right with a nonlocally pulled front.

Uniqueness and stability of time-periodic pyramidal fronts for a periodic competition-diffusion system

The existence, non-existence and qualitative properties of time periodic pyramidal traveling front solutions for the time periodic Lotka-Volterra competition-diffusion system have already been studied in $ \Bbb{R}^{N} $ with $ N\geq 3 $. In this paper, we continue to study the uniqueness and asymptotic stability of such time-periodic pyramidal traveling front in the three-dimensional whole space. For any given admissible pyramid, we show that the time periodic pyramidal traveling front is uniquely determined and it is asymptotically stable under the condition that given perturbations decay at infinity. Moreover, the time periodic pyramidal traveling front is uniquely determined as a combination of two-dimensional periodic V-form waves on the edges of the pyramid.

Asymptotic spreading of time periodic competition diffusion systems

This paper deals with the asymptotic spreading of time periodic Lotka-Volterra competition diffusion systems, which formulates the coinvasion-coexistence process. By combining auxiliary systems with comparison principle, some results on asymptotic spreading are established. Our conclusions indicate that the coinvasions of two competitors may be successful, and the interspecific competitions slow the invasion speed of one species.