Community Information Systems (CIS or observatoires du territoire in French) were designed to monitor environmental change in given agriculture-dominated areas. They serve both as information resource centres and as fora for exchange and coordination among local stakeholders. In 2004, the French Agriculture and Fishing Ministry asked CIRAD (Agricultural Research Center for Developing Countries) to assist in the set-up of CISs that would serve as pilot studies. CISs are co-constructed by local stakeholders using Unified Modelling Language to define and structure the information needed to better understand a specific problem associated with agriculture. Two years of experience of setting up CISs has allowed us to develop methods and recommendations for the set-up of such community information systems. We identify the factors that favour local and collective ownership of a social device based on data management, an area traditionally perceived as the domain of experts, i.e., "off-limits" to non-expert local stakeholders. We discuss the extent to which CISs allow a diversity of stakeholder groups to collectively address the multiple perceptions and interests and to tackle the complexities inherent in the agriculture-environment relationship.