Aquatic subsidies increase the resilience of riparian spider communities after pulse disturbance

Climatic events such as intense winds and rainfall act as strong pulse disturbances in many ecosystems. Although these disturbances can abruptly alter community structure and dynamics, recovery depends on community resilience, which may be enhanced by resource availability. Cross-ecosystem subsidies can increase prey availability for generalist predators, potentially buffering communities against the effects of disturbance. In this study, we tested whether aquatic subsidies (i.e., emergence of aquatic insects) enhance the resilience of spider communities following unpredictable climatic pulse disturbances. We conducted a field experiment in four Atlantic Rainforest streams, simulating pulse disturbances in riparian and inland plots. We surveyed vegetation-dwelling spiders one day before and four times after disturbance simulations to estimate changes in abundance and community resilience, while stable isotope analyses assessed the contribution of aquatic insects to spider diets. Riparian spiders consumed more aquatic insects than inland spiders, and spider abundance was 24% higher in riparian plots. Disturbance effects were also 43% stronger in riparian communities. Despite this stronger immediate impact, recovery models indicated greater resilience in riparian spider communities, highlighting the role of emergent aquatic insect subsidies in post-disturbance recovery. Our findings demonstrate that cross-ecosystem resource linkages can enhance the resilience of terrestrial predator communities to climatic pulse disturbance.