Population-level herbivory
Herbivory on three common plant species, Saussurea pulchra (Slope = -0.946, R2 = 0.352, P = 0.012),Taraxacum mongolicum (Slope = -0.583, R2 = 0.220, P = 0.009) and Polygonum macrophyllum (Slope = -1.273, R2 = 0.151, P = 0.041), decreased consistently with latitude (Figure 4). Precipitation of the wettest month (Slope = 0.214, R2 = 0.438, P = 0.005), mean annual precipitation (Slope = 0.030, R2 = 0.414,P = 0.006) and soil N (Slope = 1.191, R2 = 0.309, P = 0.001) increased, but temperature seasonality decreased (Slope = -0.035, R2 = 0.418, P = 0.003), herbivory on S. pulchra (Table S7; Figure S6). Mean annual precipitation (Slope = 0.016, R2 = 0.269,P = 0.004), precipitation of the wettest month (Slope = 0.099, R2 = 0.254, P = 0.004) and electrical conductivity (Slope = 0.039, R2 = 0.200, P = 0.014) increased, but temperature seasonality (Slope = -0.017, R2 = 0.238, P = 0.006) and soil pH (Slope = -2.932, R2 = 0.317, P = 0.001) decreased, herbivory on T. mongolicum (Table S8; Figure S7). Mean annual precipitation (Slope = 0.056, R2 = 0.240, P = 0.010), minimum temperature of the coldest month (Slope = 1.071, R2 = 0.187, P = 0.031) and tannin content (Slope = 0.418, R2 = 0.193, P = 0.003) increased, but temperature seasonality decreased (Slope = -0.037, R2 = 0.183, P = 0.032), herbivory on P. macrophyllum (Table S9; Figure S8). Plant community factors did not explain significant amounts of variation in herbivory for any of the three common species (Table S7, S8, S9). In addition, the biomass of each species in each site did not significantly vary with latitude.