Figure 12.9 Negative density dependence in flax. When flax seeds are sown at higher densities, the average plant is smaller. Smaller plants are less fecund, so high densities cause plant populations to increase at a slower rate. The dashed red line in each panel represents the mean dry mass.

Data from J. Harper, A Darwinian approach to plant ecology, Journal of Ecology 55 (1967): 247–270.