title: Trade-off among different anti-herbivore defence strategies along an altitudinal gradient.
abstract: The type and intensity of plant-herbivore interactions are likely to be altered under climate change as a consequence of differential dispersal rates of plants and their herbivores. Here, we studied variation in herbivore damage on Salvia nubicola in the field and compared its growth and defence strategies against herbivores in controlled conditions using seeds from populations along a broad altitudinal gradient. Our work is one of the first studies to simultaneously measure complex intraspecific variation in plant growth, direct and indirect defences as well as plant tolerance (ability to regrow) as a consequence of herbivore attack simulated by clipping. In the field, we found that plants experienced higher herbivore pressure in lower altitudes. In the greenhouse, plants grown from seeds collected in lower-altitude populations grew better and produced a higher content of phenolic compounds (direct defence) and volatile organic compounds (indirect defence) in response to simulated herbivory. However, there were no differences in tolerance and effect of S. nubicola extracts on the model generalist herbivore Spodoptera littoralis (direct defence) along the altitudinal gradient. Although we found that S. nubicola developed a range of defence strategies, the strategies do not seem to be used simultaneously in all populations even though most of them are correlated with altitudinal gradient. Our finding is in agreement with the current knowledge that co-expression of multiple defences might be costly for a plant, since investment in defensive traits is assumed to reduce the resource availability for growth and reproduction. Our study thus shows the importance of simultaneous study of different defence strategies since understanding these trade-offs could be necessary for detecting the mechanisms by which plants are able to cope with future climate change.
authors.affiliation: Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, CZ-25243, Czech Republic Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-12801, Czech Republic tomas.dostalek@gmail.com.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Dostálek
authors.affiliation: Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, CZ-25243, Czech Republic Department of Biodiversity Research, Global Change Research Institute, The Czech Academy of Sciences, Bělidla 4a, Brno, CZ-60300, Czech Republic.
authors.forename: Maan Bahadur
authors.initials: MB
authors.lastname: Rokaya
authors.affiliation: Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 313, Prague, CZ-16502, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Maršík
authors.affiliation: Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 313, Prague, CZ-16502, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Rezek
authors.affiliation: Crop Research Institute, Drnovská 507, Prague, CZ-16106, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Skuhrovec
authors.affiliation: Crop Research Institute, Drnovská 507, Prague, CZ-16106, Czech Republic.
authors.forename: Roman
authors.initials: R
authors.lastname: Pavela
authors.affiliation: Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, CZ-25243, Czech Republic Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-12801, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Münzbergová
keywords: Climate change; Lamiaceae; VOCs; defence strategies; elevation; greenhouse experiment; insect herbivory; plant–animal interactions