Table 3 Constitutive and herbivore-induced VOCs released from entire experimental plant communities grown in pots in the greenhouse. 1 sp = Trifolium pratense monoculture, TG = two species mixture of T. pratense and Geranium pratense, TD = two species mixture of T. pratense and Dactylis glomerata (TD), 3 spp (TGD) = three species mixture with T. pratense, D. glomerata and G. pratense. In half of the experimental plant communities, one single T. pratense individual was infested with Spodoptera littoralis caterpillars (Herbviory). Values represent mean VOC emissions (ng g−1 h−1) ± SEM from the experimental plant communities
From: Plant volatile emission depends on the species composition of the neighboring plant community
Compounds | Control | Herbivory | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 sp. (T) | 2 spp. | 3 spp. (TDG) | TG | TD | T (1 sp.) | 2 spp. | 3 spp. (TDG) | TG | TD | |
Monoterpenes | ||||||||||
 (Z)-β-ocimene | 1.5 ± 0.6 | 3.9 ± 1.3 | 4.4 ± 1.5 | 6.5 ± 2.2 | 1.3 ± 0.2 | 2.2 ± 1.0 | 3.4 ± 0.6 | 6.1 ± 1.4 | 3.9 ± 0.9 | 2.7 ± 0.8 |
 (E)-β-ocimene | 6.8 ± 2.3 | 18.8 ± 4.8 | 23.6 ± 4.7 | 7.6 ± 2.2 | 30.1 ± 6.9 | 13.4 ± 6.0 | 17.3 ± 3.4 | 33.4 ± 8.2 | 11.0 ± 1.4 | 24.9 ± 5.9 |
 Tricyclene | – | 2.2 ± 0.9 | 1.6 ± 0.7 | 4.4 ± 1.3 | – | – | 1.1 ± 0.5 | 2.3 ± 0.5 | 2 ± 0.7 | – |
 α-Pinene | 0.2 ± 0.2 | 1.2 ± 0.4 | 1.4 ± 0.3 | 2.0 ± 0.6 | 0.3 ± 0.2 | 0.1 ± 0.1 | 0.7 ± 0.2 | 1.3 ± 0.2 | 1.2 ± 0.2 | 0.1 ± 0.1 |
 Camphene | – | 0.2 ± 0.1 | 0.3 ± 0.2 | 0.5 ± 0.2 | – | – | 0.1 ± 0.1 | 0.3 ± 0.1 | 0.1 ± 0.1 | – |
 β-pinene | – | 0.3 ± 0.1 | 0.5 ± 0.2 | 0.7 ± 0.2 | – | – | 0.1 ± 0.1 | 0.5 ± 0.2 | 0.2 ± 0.1 | – |
 Myrcene | – | 1.4 ± 0.5 | 3.5 ± 1.4 | 1.0 ± 0.3 | 1.9 ± 0.8 | – | 0.8 ± 0.4 | 1.9 ± 0.6 | 0.2 ± 0.2 | 1.6 ± 0.8 |
 Limonene | 0.1 ± 0.1 | 2.0 ± 0.6 | 4.3 ± 1.4 | 0.4 ± 0.2 | 3.7 ± 0.8 | 0.3 ± 0.3 | 0.7 ± 0.3 | 2.2 ± 0.5 | 0.1 ± 0.1 | 1.3 ± 0.6 |
 Linalool | – | 0.5 ± 0.3 | 1.4 ± 0.4 | 0.2 ± 0.2 | 0.9 ± 0.6 | 1.1 ± 1.0 | 0.6 ± 0.4 | 0.7 ± 0.4 | – | 1.4 ± 0.7 |
Sesquitepene | ||||||||||
 (E)-β-Caryophyllene* | 0.1 ± 0.1 | 3.5 ± 1.8 | 3.8 ± 1.0 | 5.9 ± 3.3 | 1.1 ± 0.4 | 1.6 ± 0.8 | 3.0 ± 0.6 | 9.7 ± 2.1 | 3.5 ± 0.9 | 2.5 ± 0.9 |
 (E)-β-Farnesene | – | 2.2 ± 1.4 | 1.8 ± 1.2 | 4.3 ± 2.6 | – | – | 0.4 ± 0.3 | 3.7 ± 2.0 | 0.8 ± 0.5 | – |
 cucurmene | – | 1.7 ± 1.4 | 0.5 ± 0.2 | 3.4 ± 2.7 | – | – | 1.3 ± 1.0 | 1.1 ± 0.5 | 2.4 ± 1.7 | – |
 Germacrene D | – | 2.8 ± 1.6 | 4.2 ± 2.9 | 5.7 ± 2.8 | – | – | 1.2 ± 0.4 | 5.9 ± 1.4 | 2.1 ± 0.4 | 0.1 ± 0.1 |
 (E,E)-α-Farnesene | 0.7 ± 7 | 2.7 ± 1.2 | 6.1 ± 2.2 | 0.1 ± 0.1 | 5.2 ± 1.8 | – | 1.9 ± 1.1 | 6.1 ± 2.4 | – | 4.2 ± 1.9 |
Homoterpenes | ||||||||||
 DMNT* | 0.8 ± 0.3 | 0.4 ± 0.2 | 0.6 ± 0.2 | 0.3 ± 0.3 | 0.5 ± 0.2 | 2.1 ± 1.3 | 1.5 ± 0.3 | 2.2 ± 0.7 | 1.2 ± 0.3 | 1.7 ± 0.6 |
GLVs | ||||||||||
 (Z)-3-Hexenyl acetate | 17 ± 13 | 109 ± 50 | 153 ± 81 | 28 ± 21 | 190 ± 90 | 17 ± 15 | 34 ± 17 | 120 ± 43 | 4 ± 2 | 70 ± 31 |
Other volatiles | ||||||||||
 1-Octen-3-ol | – | 1 ± 0.3 | 2.6 ± 0.7 | – | 2.0 ± 0.3 | – | 0.9 ± 0.4 | 2.2 ± 0.6 | – | 1.9 ± 0.4 |
 Octly-acetate | – | 0.2 ± 0.1 | 0.5 ± 0.2 | – | 0.4 ± 0.2 | 0.5 ± 0.4 | 0.7 ± 0.2 | 0.3 ± 0.2 | 0.7 ± 0.4 | 0.6 ± 0.2 |
 Nonanal | 1.8 ± 0.7 | 1.4 ± 0.4 | 1.6 ± 0.7 | 0.9 ± 0.5 | 1.9 ± 0.6 | 1.9 ± 1.1 | 1.3 ± 0.3 | 1.6 ± 0.6 | 1.6 ± 0.5 | 1.0 ± 0.3 |
 Benzyl alcohol | 1.9 ± 1.0 | 2.5 ± 1.1 | 8.1 ± 2.8 | 1.1 ± 0.7 | 4.0 ± 1.9 | 1.0 ± 0.7 | 1.8 ± 0.8 | 12.2 ± 7.7 | 0.4 ± 0.3 | 3.5 ± 1.5 |
 Unknown | 0.5 ± 0.2 | 0.3 ± 0.1 | 0.7 ± 0.2 | 0.3 ± 0.1 | 0.3 ± 0.1 | 0.9 ± 0.5 | 0.5 ± 0.2 | 0.6 ± 0.2 | 0.4 ± 0.2 | 0.6 ± 0.3 |
 MESA | – | 0.4 ± 0.3 | 0.3 ± 0.3 | – | 0.8 ± 0.6 | – | 0.3 ± 0.2 | 0.8 ± 0.5 | – | 0.6 ± 0.3 |
Total | 31 ± 14 | 159 ± 55 | 225 ± 90 | 73 ± 35 | 244 ± 96 | 42 ± 20 | 73 ± 22 | 215 ± 50 | 35 ± 6 | 118 ± 40 |