Innovative frameworks have to be identified for the deployment and execution of pervasive service systems. These systems, composed by a massive number of components, should be able to exhibit properties of self-organization and self-adaptability, and of long-lasting evolvability. In this context, this paper discusses how such frameworks should get inspiration from natural systems. In particular, we focus on ecological systems that model and deploy services as autonomous individuals (i.e., agents), spatiallysituated in an ecosystem of other services, data sources, and pervasive devices, all of which acting, interacting, and evolving according to a limited set of "laws of nature". The key characteristics of the proposed ecological approach are detailed with the help of a representative case study. Also, an extensive set of simulation experiments are reported to outline the peculiarities of its dynamic behavior and to show the potential effectiveness of the approach.