a, Changes in relative proportion of different classes of VOCs showing significant interactive effects on monoterpenes and homoterpenes. C: control; W: warming; M: methyl jasmonate application; MW: combination of methyl jasmonate and warming. b, c, Constrained redundancy analyses (RDA) of VOC profiles in July (b) and August (c) showing clear separation (n = 18, P < 0.001, permutation tests) in VOC blends among treatments (light blue dots: control, yellow dots: warming, dark green triangles: methyl jasmonate, orange triangles: combination of warming and methyl jasmonate), as well as the association of treatments with VOC compound classes. Aco: alcohols; Ade: aldehydes; Aka: alkanes; Ake: alkenes; Bze: benzenoids; Fra: furans; Ket: ketones; Iso: isoprene; HT: homoterpenes; MT: monoterpenes; ST: sesquiterpenes. See Supplementary Fig. 3 for RDA analyses based on individual compounds.