Remarks on the Behavior of an Agent-Based Model of Spatial Distribution of Species

João Bioco,Fernando Cánovas,Paulo Fazendeiro,Paula Prata

doi:10.33166/aetic.2021.02.004

Abstract

Agent-based models have gained considerable notoriety in ecological modeling as well as in several other fields yearning for the ability to capture the emergent behavior of a complex system in which individuals interact with each other and with their environment. These models are implemented by applying a bottom-up approach, where the entire behavior of the system emerges from the local interaction between their components (agents or individuals). Usually, these interactions between individuals and their enclosing environment are modeled by very simple local rules. From the conceptual point of view, another appealing characteristic of this simulation approach is that it is well aligned with the reality whenever the system is composed of a multitude of individuals (behavioral units) that can be flexibly combined and placed in the environment. Due to their inherent flexibility, and despite of their simplicity, it is necessary to pay attention to the adjustments in their parameters which may result in unforeseen changes on the overall behavior of these models. In this paper we study the behavior of an agent-based model of spatial distribution of species, by analyzing the effects of the model parameters and the implications of the environment variables (that compose the environment where the species lives) on the models’ output. The presented experiments show that the behavior of the model depends mainly on the conditions of the environment where the species live, and the main parameters presented in life cycle of the species.

Highlights

Agents have their own behaviors and act in order to accomplish a purpose
The species life cycle consists of three main steps: (1) at each time the species reproduce according to the birth rate and the conditions of its cell; (2) an amount of species dies according to the death rate and the suitability of the cell; and (3) neighboring cells receive each one an amount of individuals according to the spread rate, see Figure 1
In this study we analyzed the effects of an agent-based model’s parameters in the spatial distribution of species, by implementing an ABM able to deal with a heterogeneous environment represented by a combination ofvariables of interest

Summary

Introduction

Agents have their own behaviors and act in order to accomplish a purpose. Agent-based models (ABM) describe individuals (agents) as a unique and autonomous entities that normally interact with each other and their environment [1]. ABM are considered computational models that show how the dynamics of a system have emerged resulting from the interactions of its entities (agents) in a shared environment [2]. In the ecological modeling field, agent-based models ( referred as individual-based models) are simulation models that consider agents or individuals as unique and discrete entities with proprieties that change during its life cycle [6]. Four classification criteria are taken into account to distinguish classical models and agent-based models in ecology: (1) the individuals life cycle reflected in the model, (2) the considered resources (like food, João Bioco, Paula Prata, Fernando Cánovas and Paulo Fazendeiro, “Remarks on the behavior of an agent-based model of spatial distribution of species”, Annals of Emerging Technologies in Computing (AETiC), Print ISSN: 2516-0281, Online ISSN: 2516029X, pp.

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Conclusion