Oscillation-induced yield loss in China partially driven by migratory pests from mainland Southeast Asia

Abstract

Large-scale climate oscillations are recognized as skilful predictors of variations in global and regional crop yield. However, the mechanisms linking climate oscillations to crop yield variations remain unclear and are widely assumed to result from crop physiological responses to oscillation-induced local climate variations. Here we assessed the pattern of oscillation-induced yield variations in China over the past four decades and found that El Niño/Southern Oscillation (ENSO) is the primary climatic oscillation associated with extreme yield anomalies, particularly in southern China. These ENSO-related extreme yield anomalies are driven not only by local climate anomalies but also by greater occurrences of crop pests and diseases. Interestingly, the greater occurrence of crop pests is not triggered by local climate anomalies but is linked to ENSO-forced climate anomalies in mainland Southeast Asia, the source region of these pests, fuelled by the ENSO-driven circulation pattern facilitating their migration to China. Given the projected increase in the frequency of ENSO events in a warming future, effectively mitigating such oscillation-induced crop failures requires cross-border collaboration between the source and receiving countries of crop pests. Climate oscillations, such as El Niño/Southern Oscillation (ENSO), play a key role in global and regional crop yield variations. The authors analysed crop yield data in China from 1980 to 2017 and found that ENSO affects yield not only through local climate variability but also by driving migratory crop pest outbreaks, highlighting an overlooked pathway by which ENSO drives yield loss.