We propose this oral session to promote exploration and synthesis of the major ecological drivers of non-additive mixed litter decomposition to improve predictions and applications in the natural world. Empirical investigations and reviews of biodiversity and ecosystem function have focused primarily on the responses of primary productivity, ecosystem stability, and nutrient use; and there is consensus that patterns are complex, but better mechanistic understanding is needed if emergent effects are to be found. A large number of mixed litter decomposition studies have found non-additive effects (both positive and negative) of species mixtures on litter decomposition, but demonstrated mechanistic explanations still elude scientists. Our first aim, then, is to bring together various leading scientists concurrently working on the mechanistic drivers of non-additive mixed litter decomposition. Second, we would like to address potential applications of litter diversity. Leaf litter inputs represent 50 to 80% of the recycled input of nutrients in many forest ecosystems and litter decomposition is the primary link between productivity and ecosystem nutrient recycling. Thus, restoration and replanting efforts must consider the identity and diversity of focal species. For example, applications of mixed-litter mulch on maize fields has been shown to increase seedling performance, though whether this effect would extend toward other crop species or other litter mixtures remains unclear. In this session we propose to explore a variety of application questions that will be complemented by improvements in our mechanistic understanding. For example, speakers will address the following questions: What level of diversity is important to litter mixing? What other trophic levels are important to promote in restoration plans? What is the role of invasive species in litter mixtures? Do different classes of organisms respond differently to litter mixtures (i.e. soil macrofauna and microbial decomposers)? Finally, this session will showcase both established ecologists and researchers new to the field and will thus promote discourse between scientists from disparate backgrounds and places of origin.