Tolerance to simulated herbivory in two populations of Convolvulus chilensis (Convolvulaceae)

Tolerance to damage allows plants to endure herbivory without major fitness consequences and may be associated with changes in plant morphology. We evaluated in a greenhouse experiment the tolerance to damage (clipping of 25% of aboveground biomass) and phenotypic changes after damage in plants from two populations of the endemic Chilean species Convolvulus chilensis (Convolvulaceae). The populations differ, among several environmental features, in the type of damage experienced by plants: clipping by humans vs. mammal herbivory. We also evaluated whether the effect of damage in plants is affected by light availability. Both populations were equally tolerant to damage in terms of survival and plant growth, and tolerance was not different under sun and shade. Damage significantly affected plant architecture (an increase in number of stems/plant height), and there was no differential effect of damage according to population of origin. The light environment did not influence the effect of damage on plant architecture. The latter finding contrasts with similar work on other species and might be related to the reported remarkable ability of C. chilensis to cope with shading conditions. Results preliminary suggest that the occurrence of tolerance in C. chilensis might be a generalized response to repeated damage regardless of the particular type of damage.