The El Niño–Southern Oscillation (ENSO) is the largest source of interannual climate variability in much of the tropics. We hypothesize that tropical plants exhibit interannual variation
in reproduction and resource acquisition strategies driven by ENSO that mirrors their seasonal responses. We analyze the relationship of leaf and seed fall to climate variation over 30
years in a seasonally dry tropical forest in Panama where El Niño brings warm, dry, and sunny
conditions. Elevated leaf fall precedes the onset of El Niño, and elevated seed production
follows, paralleling associations with dry seasons. Our results provide evidence of a shift in
allocation from leafing to fruiting in response to a warming phase of ENSO. This shift may
enable plants to take advantage of higher light availability, while coping with higher atmospheric water demand and lower water supply. These findings might be an indicator of
adaptive strategies to optimize reproduction and resource acquisition.
