RE-NOURISH · Nutrient redistribution by mammals as a key mechanism for ecosystem restoration

Declining soil fertility represents one of humanity’s major challenges in the 21st century. In the past, large vertebrate animals played a crucial role in transporting nutrients between ecosystems, supporting a more fertile planet. Today, however, species extinctions, diminished population abundances and constraints on animal movement have reduced animal-mediated nutrient transport by >90% compared to the late-Pleistocene. In contrast, anthropogenic use of certain nutrients (nitrogen [N], phosphorus [P] and potassium [K]) vastly exceeds planetary boundaries. Consequently, some areas of the world experience excessive nutrient pollution and others nutrient depletion. Agricultural abandonment trajectories provide opportunities for large-scale ecosystem restoration, including rewilding of large vertebrates. However, where humans have altered nutrient geographies, redistribution by wild animals may have unintended consequences for nearby ecosystems, including to plant productivity, carrying capacity, carbon storage and endemic competitive advantages. Consequently, changes to either anthropogenic nutrient loading or to animal dynamics during ecosystem restoration projects can have far-reaching implications.RE-NOURISH will develop an agent-based modelling framework that quantifies the redistribution of multiple nutrients across landscapes by different guilds of large mammals. Crucially, this model will include the direct and indirect influences of predators – an essential, but often overlooked aspect of nutrient redistribution in terrestrial landscapes. The RE-NOURISH framework will then be applied to two restoration case studies in (i) nutrient-deficient and (ii) nutrient-polluted environments. This transformative approach will directly help conservation practitioners achieve goals of ecological integrity and contribution to climate stability. Results will be disseminated via published papers, interactive workshops, conference presentations and popular articles.