Induced response in Schima superba: effects of early-season herbivory on leaf traits and subsequent insect attack.

Abstract

Physical, nutritional and allelochemical reactions generally occur in plant leaves in response to herbivory, and such responses can reduce to a certain extent, the performance and/or preference of subsequent herbivores. This study gave an additional evidence to the induced defense theory through the simulated herbivory in Schima superba , one of the common dominant trees in subtropical evergreen broadleaf forests, southern China. The results showed that the leaves that were damaged in the beginning of the leaf expansion had higher toughness and concentration of tannins, but lower water content and nitrogen content when compared with the control leaves. As a result, the damaged shoots had lower rates of herbivory but a higher shoot growth rate than control shoots. The results may imply that early-season herbivory on the leaves of S. superba reduced the nutritional quality of leaves and increased the amount of secondary compounds, therefore influencing later-season herbivory through the induction of plant responses that may act to reduce plant quality as food for herbivores. Keywords: Induced response, herbivory, early-season damage, nitrogen content, Schima superba