Figure 2 Effects of shading and snail biomass on shoot number
and internode length of P. crispus . shoot number (A) and
internode length (B) . S0 indicates full light, S1 indicates low
light intensity under shading. Lines are fitted by gam functions in
package ggplot2, and a solid line indicates p < 0.05,
and a dashed line indicates p > 0.05. Dot symbol
indicates nutrient loading, and triangles indicate no additional
nutrients were added. P values in the panel indicate a
significant effect of shading on the mean of the response variable.