High-intensity agriculture consisting of annual monocultures has drastically increased food production, but has been shown to deplete and pollute water resources, degrade soils, increase greenhouse gas emissions, and damage natural ecosystems. Perennial polycultures represent an understudied but potentially transformative multifunctional agroecosystem that can provide food, forage, and fiber while also providing important ecological, economic, and social benefits. This concept is based on the premise that restoring biodiversity will enhance food and ecosystem service production, largely through complementarity in resource use. In addition, planting perennial rather than annual crops can improve soil stability and resource use efficiency on the ecosystem-scale. In this session, we will explore the application of ecological theory developed in natural ecosystems to managed agroecosystems with the goal of better understanding species interactions in perennial polyculture agroecosystems and mechanisms that drive potential food and ecosystem services production in these systems. We will also address questions relating to optimal system design, identify differences between woody versus herbaceous systems as well as tropical versus temperate systems, and evaluate the social and economic dimensions of transitioning to perennial polycultures. This session will focus on the ecology of temperate-zone perennial agriculture, with an emphasis on agroforestry for food production, which is a novel agroecosystem gaining traction in the Midwest U.S.