Heatwaves cause tropical trees to release disproportionately higher levels of acyclic monoterpenes compared to cyclic forms, according to research published in Nature Communications on August 21, 2026. Researchers at the Guangzhou Institute of Geochemistry and the University of Chinese Academy of Sciences found that acyclic monoterpenes from tropical trees in South China show substantially greater temperature sensitivity than cyclic variants.
Acyclic and cyclic monoterpenes differ in their chemical reactivity, biosynthetic pathways, physiological functions, and atmospheric impacts. During heat extremes, ambient atmospheric mixtures shift heavily toward acyclic compounds. These acyclic emissions approach half of all measured monoterpenes under heatwave conditions and dominate calculated ozone and hydroxyl-radical reactivity.
Standard atmospheric emission models assign similar temperature sensitivities to both monoterpene classes. Because of this baseline assumption, default algorithms fail to reproduce the cyclic-to-acyclic shift observed in field data. The study authors demonstrated that revised temperature-response functions successfully replicate the increased acyclic fraction under high temperatures.
The study was authored by Jianqiang Zeng, Xiaoyang Wang, Yuting Lu, Weihua Pang, Wei Song, Yanli Zhang, Ping’an Peng, and Xinming Wang. Funding was provided by the National Natural Science Foundation of China, the National Key Research and Development Program, the Postdoctoral Fellowship Program of CPSF, and the Department of Science and Technology of Guangdong, with logistical support from HNFRFE.
