Seedling species determines rates of leaf herbivory in a Malaysian rain forest

Abstract

Seedlings of five species in the Dipterocarpaceae were grown in experimental plots in Sabah, Malaysia. These were sited both in gaps and understorey and on alluvial and sandstone soils. Half of all seedlings were provided with a complete fertilizer. Herbivore damage levels were recorded on over 25 000 individual leaves in four surveys over the course of 2 y. Rates of herbivory were lower on mature leaves (0.07–0.8% leaf area mo⁻¹ among species) than new leaves (2.1–4.4% leaf area mo⁻¹). There were no overall effects of light conditions, soil type, fertilizer treatment or time on rates of herbivory. The only consistent source of variation was that between species, with the three alluvial-specialist species suffering higher rates of damage than the two sandstone-specialists. Mature leaves of alluvial species received greater damage in sandstone soils, whereas sandstone species were damaged at equivalent rates on both soil types. New leaves were more damaged on their native soil type. Published herbivory rates vary in the timescales and methods of measurement. Nevertheless, the few comparable studies confirm that herbivory rates on seedlings in tropical rain forests are remarkably constant over time and across experimental treatments.