Human activities have caused tremendous changes in the abundance and distribution of large mammalian herbivores throughout the world (Dirzo et al. 2014, Ripple et al. 2015, Young et al. 2016). Many species have been driven extinct, become imperiled or introduced to new regions outside their native range. These alterations are of great concern because large mammalian herbivores can serve as major drivers of vegetation structure and dynamics, biological invasions and prevailing disturbance regimes (Ripple et al. 2015). These changes can also trigger a series of cascading, indirect effects on the abundance and composition of other co-occurring animal taxa, as well as a wide range of ecosystem-level effects, which may ultimately lead to entire state changes (Foster et al. 2014, Keesing and Young 2014, Ripple et al 2015, Young et al. 2015, Daskin and Pringle 2016). In this session, we propose to explore and synthesize the range of cascading effects that large mammalian herbivores have on terrestrial landscapes. We will bring together leading experts in the field who are conducting long-term empirical studies in both North America and Africa. Many of the presentations will explore the effects of large herbivores on a suite of community- and ecosystem-scale responses – including plant invasions, the abundance of co-occurring animal species, productivity, carbon storage, soil processes and fire. Other presentations will present results from historical studies that explore how the loss or change in the behavior of large herbivores can transform ecosystem processes and even lead to ecological state changes. Lastly, given that the effects of large herbivores are often variable within or among ecosystems, numerous presentations will summarize efforts to understand the drivers of these context-dependent outcomes and determine the extent to which effects are scale dependent.