Abstract:
Herbivory is an important plant-animal interaction which impacts ecosystems in various ways, e.g., influencing nutrient cycles, plant productivity, and community composition. Herbivory therefore plays a crucial role in maintaining ecosystem functions of tropical rainforests. As plants are negatively impacted by herbivory, they have developed antiherbivore defense strategies, which reduce herbivory levels. Additionally, herbivory is known to decrease under harsh climatic conditions, because herbivorous arthropods are impacted by temperature and precipitation. However, it has yet to be clarified whether herbivory is primarily impacted directly by climatic (i.e., abiotic) factors or indirectly through plant traits (i.e., biotic factors). In this study we investigated the influence of temperature, precipitation, and various leaf traits, like specific leaf area (SLA) and nutrient concentration, on herbivory along an elevational gradient from 1000 to 3000 m a.s.l. in a tropical rainforest in South Ecuador. We found lower herbivory levels at higher elevation in response to decreased temperature and SLA. Moreover, herbivory levels decreased with precipitation. Hence, we demonstrated that climate has a significant direct and indirect impact on tropical ecosystems by influencing herbivory.
