El Niño Southern Oscillation Dynamics in NW-Peru over 2 Decades: Desert and Dry Forest Response to Extreme Heat and Rainfall Events.

The terrestrial ENSO core impact region of North-West Peru is characterized by exceptionally strong inter-annual variation in rainfall resources and in vegetation cover. Based on long-term field data we characterize ENSO related pulse dynamics and identify threshold responses between alternate ecosystem states in deserts and dry forests.

By framing and focusing on extreme climatic events within our ecological long time-series on climatic conditions and vegetation responses, we contribute to understanding pulse dynamics in ecosystems. The threshold responses in primary production of deserts and tropical dry forests in Peru are best explained by ENSO driven river discharge, fed by additional, non-ENSO driven water resources. Our study sugests, that dryland ecosystems show critical transitions between alternate states.

Understanding of how ENSO-driven pulse dynamics interact with other environmental drivers in shaping ecosystem dynamics is crucial for supporting land management and conservation in areas, where the variability in mean annual precipitation is among the highest globally.