. The distribution of differences from average for a given survey may be greater or less than zero, indicating that quadrats are being measured consistently higher or lower for the conditions in which the survey was performed](ECE0-0-0000-g000){#ece00000-fig-0000}  ![Boxplot distributions of 0 × 0 m quadrat rugosity measurement differences δSR ~*j,i*~ per survey (*i *=* *0 to 0) from quadrat average across all surveys, for surveys 