Global latitudinal patterns in leaf herbivory are related to variation in climate, rather than phytochemicals or mycorrhizal types

In summary, a hump-shaped latitudinal pattern in leaf herbivory was observed based on currently available data, inconsistent with the latitudinal herbivory hypothesis. It is climate, rather than phytochemical diversity or plant mycorrhizal types, that mostly shapes the global pattern of plant-herbivore interactions. Most importantly, latitudinal variations in temperature and precipitation can limit the diversity, abundance and activity of herbivores and thus the herbivory intensity (13). The limited power of phytochemical data at the plant family level here pointed to a more straightforward and effective way of sampling detailed species-level phytochemical data along latitudes in future studies, which could help to address the unexplained variation in herbivory. Mycorrhizal-mediated plant interactions with aboveground herbivores are not that striking compared to well-known interactions with soil antagonists (e.g., pathogens), perhaps because the plant root system is a more direct interface for interactions between mycorrhizal fungi and belowground antagonists (8). Together, our unique perspectives involving phytochemicals and mycorrhizal associations will inspire future studies to focus on more accurate species-level data to understand their role in modifying plant-herbivore interactions and consequently ecosystem functions at a macroecological scale.