process of speciation greatly broadens the timescales being considered when conserving ecosystems in the face of global change. This focus on speciation allows for the recovery time or extinction debt of a community to be considered in the long term when attempting to understand how a given ecosystem will respond to human impacts. This integrative approach is important because human activities can impact all of these fundamental processes, which in turn generate observed biodiversity responses such as species loss and community turnover. Making cross-ecosystem and process-based comparisons using our approach (Figure 1) will therefore help to develop a more mechanistic understanding of how humans impact biodiversity and ecosystem dynamics (Soininen et al. 2015; Twining et al. 2019). For example, knowing if fundamental differences exist in the strength of dispersal limitation between ecosystem types may help to understand how species track changing thermal environments during warming, or how invasive species spread across the two ecosystems. Further, identifying differences, as well as similarities, in how processes operate will facilitate collaboration between terrestrial and freshwater scientists who share the goal of reducing negative impacts on diversity (Mengeet al. 2009; Mokany et al. 2010).