Seabirds and native vegetation drive ecosystem processes that support atoll island resilience

Ecosystem restoration is expected to enhance ecosystem resilience to climate change, but few empirical and mechanistic demonstrations of such assertions exist. Here, we explore this topic for tropical atoll systems, combining science on nutrient subsidies and geo-ecological functions through a unifying ecological energetics lens. We show that native forest cover and seabird nutrient inputs increase primary productivity and secondary metabolism on islands and adjacent coral reefs, scaling with key ecosystem processes. We then demonstrate that seabird and native forest restoration could contribute to reducing island climate change vulnerability by (i) increasing reef accretion rates such that they keep pace with sea-level rise under a 2.0°C warming scenario, (ii) enhancing the production rate of sediment, which could contribute to island maintenance, and (iii) increasing vegetation fine root length, aiding island sediment stabilization. Collectively, our findings provide an integrated energetics and geo-ecological perspective that suggests rewilding of atolls can contribute to climate resilience.