6. Conclusion: Towards greater use of invertebrates and microbes
If ecological restoration is to move forward as a more complete science, it is critical that we further investigate the role that rewilded invertebrates and microbes play during restoration. Recent advances in the field of restoration ecology have explored both the potential of whole-of-community rewilding as a restorative tool (Wubs et al. , 2016) and how benthic stream invertebrates can be translocated as whole communities (Dumeier, Lorenz and Kiel, 2020). We hope that the ideas and practical case studies proposed in this article will spur further empirical testing of whole-of-community rewilding which extend beyond soil inoculation studies. Monitoring throughout the life of invertebrate and microbial rewilding projects will be vital to determining their efficacy and the conditions under which it will enhance recovery rates. Ecosystem functions mediated by rewilded vertebrates can vary across abiotic gradients (Decker, Eldridge and Gibb, 2019). Whether the restorative potential of rewilded invertebrates and microbes varies spatially, and temporally, should therefore be explored.
Restoration projects currently overlook two groups that make up the bulk of biodiversity (Kollmann et al. , 2016). This brings into question whether most restoration projects are failing to attain their end goal: the reinstatement of biodiversity and ecosystem function in its entirety. Our argument for rewilding invertebrates and microbes addresses this shortfall, but we stress that their use should be considered for the novel advantages alone. Whole-of-community rewilding is a unique and potentially very powerful tool that land managers are largely unaware of. A greater incorporation of invertebrates and microbes in rewilding projects may also simultaneously answer the resounding call for more thorough monitoring of this underappreciated group (Eisenhauer, 2019). This would also help to fill substantial gaps in baseline knowledge of what species are present and what their functional role is before they are lost, thus assisting future recovery efforts of globally declining invertebrate populations (van Klink et al. , 2020). We hope that the ideas raised in this discussion engender a greater appreciation for the restoration and rewilding potential that invertebrates and microbes deserve. This can help mould restoration ecology into a more holistic science that values the role of all biota, irrespective of size.