This paper describes the implementation of an argumentation system used for participatory management of environmental protected areas, more precisely to model the decision of a park manager artificial agent. This implementation is based on a BDI agent architecture, namely the Jason/AgentSpeak framework/language. After introducing the principles of BDI architecture and of argumentation systems, we will detail how we model arguments within the BDI (Belief-Desire-Intention) architecture. Then, we present the argumentation-based model of deliberation and decision by the park manager agent as a case study. We show how our argument-based approach allows to model various cognitive profiles of park managers (more conservationist or more sensitive to social issues), through different knowledge bases. We show examples of decisions produced by the park manager agent and examples of traces of arguments used during deliberation, which could be a base for explaining decisions. Before concluding, we point out future directions, such as using argumentation as a basis for negotiation between various agents.