Habitat degradation and the associated reductions in ecosystem function can be reversed by reintroducing or ‘rewilding’ keystone species. Rewilding projects have historically targeted restoration of processes such as grazing regimes or top-down predation effects. Few projects have focussed on restoring decomposition efficiency, despite the pivotal role decomposition plays in global carbon sequestration and nutrient cycling. Here, we tested whether rewilding entire communities of detritivorous invertebrates and microbes can improve litter decomposition efficiency and restore detritivore communities during ecological restoration. Rewilding was conducted by transplanting leaf litter and soil, including associated invertebrate and microbial communities from species-rich remnant sites into species-poor, and geographically isolated, revegetated farmland sites. We sampled pre- and post-rewilding communities, comparing remnant, rewilded revegetation, and control revegetation sites for litter decomposition and the abundance and diversity of detritivorous invertebrates and microbes. We also quantified the effect of detritivores on the rate of litter decomposition using piecewise Structural Equation Modelling. Decomposition was significantly faster in rewilding sites than both control and remnant areas and was largely driven by a greater abundance of invertebrate detritivores. Similarly, the abundance of invertebrate detritivores in rewilding revegetation sites exceeded the level of remnant communities, whereas there was little difference between control and remnant sites. In contrast, saprotrophic fungi contributed little to decomposition. Areas selected for agriculture were likely more productive than remnant sites, suggesting that restoration sites have the capacity for higher decomposition rates and more abundant detritivore communities than target remnant sites. Importantly, our findings suggest that the novel and relatively simple act of transplanting leaf litter can increase functional efficiency during restoration and alter community composition. Our methods may prove important across a range of contexts where other restoration methods have failed to restore ecosystem processes to pre-degradation levels.

1. Restoration ecology has historically focused on reconstructing communities of highly visible taxa whilst less visible taxa, such as invertebrates and microbes, are ignored. This is problematic as invertebrates and microbes make up the vast bulk of biodiversity and drive many key ecosystem processes, yet they are rarely actively reintroduced following restoration, potentially limiting ecosystem function and biodiversity in these areas. 2. In this review, we discuss the current (limited) incorporation of invertebrates and microbes in restoration and rewilding projects. We argue that these groups should be actively rewilded during restoration to improve biodiversity and ecosystem function outcomes and highlight how they can be used to greater effect in the future. For example, invertebrates and microbes are easily manipulated, meaning whole communities can potentially be rewilded through habitat transplants in a practice that we refer to as “whole-of-community” rewilding. 3. We provide a framework for whole-of-community rewilding and describe empirical case studies as practical applications of this under-researched restoration tool that land managers can use to improve restoration outcomes. 4. We hope this new perspective on whole-of-community restoration will promote applied research into restoration that incorporates all biota, irrespective of size, whilst also enabling a better understanding of fundamental ecological theory, such as colonisation- competition trade-offs. This may be a necessary consideration as invertebrates that are important in providing ecosystem services are declining globally; targeting invertebrate communities during restoration may be crucial in stemming this decline.