Synergizing vegetation restoration and wildlife conservation to enhance natural climate solutions

To help achieve carbon neutrality and mitigate climate change, vegetation restoration and wildlife conservation have recently been promoted as two key natural climate solutions. Although ecological studies have widely reported the profound top-down impacts of wildlife on the structure and function of vegetation, vegetation restoration and wildlife conservation are often viewed and implemented as two independent natural climate solutions. Combining field experiments in degraded coastal wetlands and meta-analyses of experimental studies from vegetated ecosystems globally, we explore the impacts of wildlife on vegetation restoration and related carbon cycling processes. In the field experiments, we find that vegetation restoration through planting alone failed to lead to vegetation recovery due to grazing by herbivores and did not increase plant and soil carbon stocks. In contrast, co-restoring threatened predators or simulating their consumptive or nonconsumptive effects facilitated the establishment of planted seedlings, led to successful recovery of vegetation, and increased plant and soil carbon stocks. These effects of herbivores and predators on vegetation restoration were generally supported in our global syntheses of experimental studies from all vegetated ecosystems, although these effects were context-dependent and often varied with biotic and climatic factors such as herbivore density, temperature, and precipitation. Taken together, these results suggest that vegetation restoration, if synergized with wildlife conservation, can be more promising for enhancing carbon sequestration in many ecosystems. We conclude by outlining possible ways to achieve synergies of vegetation restoration and wildlife conservation and by highlighting their policy implications.