Nighttime warming impedes invasion of Chromolaena odorata into tropical coral islands

Nighttime warming, resulted from asymmetric global warming, is recognized as narrow diurnal temperature range (DTR). However, consensus on the effects of reduced DTR on plant's invasion remains elusive. Tropical coral islands in China, characterized as narrow DTR, are more and more intensively affected by plant invasion. In this study, we simulated a tropical coral island habitat by applying nighttime warming experiment (3 °C) and detected the responses of 19 plant functional traits of an invasive species Chromolaena odorata and a native species Scaevola sericea to this warming. Under mono-culture, C. odorata mainly adjusted water-use efficiency (WUE) to reduce water loss, while S. sericea mainly adjusted gas exchange to maintain relative growth rate (RGR) by altering leaf structural traits, in responses to nighttime warming. Under mixing-culture, nighttime warming decreased and increased resource utilization capacity of C. odorata and S. sericea, respectively. These results highlight that nighttime warming may impede the invasion of C. odorata to tropical coral islands. The recovery and construction of plantation preferentially selecting S. sericea can benefit inhibiting the spread of C. odorata at tropical coral islands.