Climate-affected multi-decadal variations of biogenic volatile organic compounds in Pinus tabuliformis growth rings

Long-term dynamics of biogenic volatile organic compounds (BVOCs) in trees are rarely reported, despite environmental factors (such as climate change) influencing their growth and the subsequent chemical accumulation. For this, tree growth rings provide a promising biological proxy for the long-time variation and correlation with environmental changes. Therefore, tree rings from Pinus tabuliformis (two stem disks and 40 tree cores) were collected in the Taihang Mountain Macaque National Nature Reserve of China. These samples were divided into seven 5-year resolutions over the 34-year period 1985 to 2018. This enabled analysis of multi-decadal variations of compounds and their correlation with climate variability. A total of 292 BVOCs were detected; however, only 18 compounds were found together across all the 7 growth-periods. Temporal analyses showed decreasing trends for monoterpenes (0.026%/yr) and diterpenes (0.120%/yr), whereas alcohols and oxygenated monoterpenes showed increasing trends at 0.031%/yr and 0.042%/yr, respectively. Correlation analyses showed no obvious link to yearly precipitation, while seasonal temperature had a negative effect on monoterpenes and diterpenes but positive effects on alcohols and oxygenated monoterpenes (all P < 0.05). The present study showed that dendrochronology is a suitable method for re-establishing the biological effects from historical climate variability on key tree species.