=+13.73 The accompanying figure is from the article “Root and Shoot Competition Intensity Along a Soil Depth Gradient” (Ecology [1995]: 673–682). It shows the relationship between above-ground biomass and soil depth within the experimental plots. The relationship is described by the linear equation: biomass 5 29.85 1 25.29(soil depth) and r 2 5 .65; P , 0.001; n 5 55. Do