The study of species interactions has greatly improved our appreciation of the importance of network structure for ecological community stability, sensitivity to invasion, and extinction. Because species interactions reflect past evolutionary constraints and niche partitioning within a particular local context, they constitute the underlying fabric of ecosystem dynamics, driving biomass and body size distributions, and ecosystem level processes. Here I propose that beyond being a simple witness of global change, species interactions can actually mediate their effects on population and ecosystem dynamics either locally via bottom-up or top-down mechanisms or regionally via spatial cascade processes. I will present case studies for each scenario and conclude with a discussion of future perspectives and challenges for the use of ecological networks in conservation biology.