Plant Diversity Is More Important than Climate Factors in Driving Insect Richness Pattern along a Latitudinal Gradient

The insect data of 93 national nature reserves in China was used to identify the underlying drivers’ potential for species richness along geographical gradients. We assessed the correlations between predictors (climate and soil) and response variables (insect richness). We found that the following: insect diversity decreased significantly at higher latitudes. The latitudinal variation in insect richness seems to be driven by climate and soil variations and also the diversity of other biota. Among all the tested predictors, plant diversity explained the most latitudinal patterns of insect richness (R2 = 0.498). Insect richness showed a positive correlation with the diversity of other biota and climate factors (mean annual temperature and mean annual precipitation) and was negatively associated with soil pH. Overall, the interspecific relationship between organisms was the main driver of insect diversity’s latitudinal pattern. However, the effects of climate and soil factors cannot be ignored.