Using stylized agent-based models for population–environment research: a case study from the Galápagos Islands

Abstract

Agent Based Models (ABMs) are powerful tools for population-environment research but are subject to trade-offs between model complexity and abstraction. This study strikes a compromise between abstract and highly specified ABMs by designing a spatially explicit, stylized ABM and using it to explore policy scenarios in a setting that is facing substantial conservation and development challenges. Specifically, we present an ABM that reflects key Land Use / Land Cover (LULC) dynamics and livelihood decisions on Isabela Island in the Galápagos Archipelago of Ecuador. We implement the model using the NetLogo software platform, a free program that requires relatively little programming experience. The landscape is composed of a satellite-derived distribution of a problematic invasive species (common guava) and a stylized representation of the Galápagos National Park, the community of Puerto Villamil, the agricultural zone, and the marine area. The agent module is based on publicly available data and household interviews, and represents the primary livelihoods of the population in the Galápagos Islands -tourism, fisheries, and agriculture. We use the model to enact hypothetical agricultural subsidy scenarios aimed at controlling invasive (1) sharpening conceptualizations of population-environment systems, (2) testing alternative scenarios, and (3) uncovering critical data gaps.

Interactions of social, terrestrial, and marine sub-systems in the Galapagos Islands, Ecuador

“…Due to its central role in the development of the Galapagos, the tourism industry is the driving force in determining the dynamics of change in all other employment sectors of the islands, particularly, generating high flows of migration from the mainland to the islands, increasing the introduction of invasive species, accelerating the consumption of resources, and increasing the pressure on basic services (27). Because of these factors, the SDGI uses trends in the number of tourists to project the impacts on linked social-ecological systems.…”

“…To design and implement the SDGI, theory regarding the development of a tourism destination (28)(29)(30) was combined with systems theory and the technique of system dynamics simulation (27). This resulting theoretical framework describes the possible evolutions of social-ecological impacts related to the development of the Galapagos tourism industry (26,27,31).…”

“…This resulting theoretical framework describes the possible evolutions of social-ecological impacts related to the development of the Galapagos tourism industry (26,27,31). A demographic module was created, with projections generated to the year 2033, to represent the dynamics of the tourism industry and associated population growth through migration from the mainland.…”

Propuesta de un Método para la Aplicación de un Modelo de Simulación Basada en Agentes del Sistema Regional de Innovación

“…[72] Así pues, el camino está trazado y se recomienda que es importante acompañar modelos basados en agentes para aplicaciones en las ciencias sociales desde la argumentación más amena y entendible y no tan matemática y estadística como se realizó para el presente trabajo, [73] para así acercar mucho más la academia con el diario vivir y que se entienda que existe la necesidad de que el público en general tenga más interacción con estas temáticas [74] [75].…”

Integrating Research Tools to Support the Management of Social-Ecological Systems Under Climate Change

“…These models range from basic and abstracted simulations, which can be used to explore the simple rules that underpin complex patterns (Schelling 1971, Epstein andAxtell 1996), to complicated and highly parameterized simulations of particular places and populations (Walsh et al 2013). Agent-based models have been applied in many fields and are particularly useful for the exploration of policy and management options (Boone et al 2002, 2006, 2013, Anselme et al 2010, Miller et al 2010). …”