A new study by Kazik and Steve published in Ecography contributes to the biogeography of plant antiherbivore strategies.
By applying a combination of field surveys and lab experiments we tested a prediction that resistance and tolerance to herbivory increase from high to low lattitudes in a salt marsh shrub Iva frutescens. In the field, average levels of herbivore damage, and spatial and temporal variation in herbivore damage were all greater at low latitudes, indicating that both constitutive and induced resistance should follow this pattern. A series of laboratory two-choice preference tests with Iva specialist beetle Paria revealed that both types of resistance were indeed stronger at lower latitudes. Contrary to expectations however, tolerance to herbivory in Iva (measured as leaf regrowth after a herbivory damage) did not depend on geographic origin. Our results emphasize the value of considering multiple ways in which plants respond to herbivores when examining geographic variation in plant–herbivore interactions.
Kazimierz Wieski and Steven C. Pennings. 2014. Latitudinal variation in resistance and tolerance to herbivory of a salt marsh shrub. Ecography. Early View. DOI: 10.1111/ecog.00498.