Fig. 4

Barnacles basal area (mm) after 12 months of experiments starting. Barnacles from the lower high intertidal were larger than those from the upper zone, and those from exclusions were larger than those from experimental controls and these larger than those from controls. Different letters indicate differences among heights and treatments (two-way ANOVA on log transformed data, Tuckey HSD test, P < 0.01). White boxes: lower high intertidal; gray boxes: upper high intertidal; C controls, EC experimental controls; E exclusions. Error bars represent 1st and 99th percentiles, boxes are 25th and 75th percentiles and symbols within boxes are the median