Figure 2
Distribution of the values of the average degree of specialization (I CS ) of arable weed communities. Box plots represent the comparison between the ICS of weed communities of the 1970 s and of the 2000 s (n = 158 fields) and between maize cropped as a monoculture (n = 235 fields) or within a two-year maize/winter wheat crop rotation (n = 169 fields). Boxes represent interquartile range, containing 50% of values; the line across boxes is the median values; the whiskers are drawn from the top of the box up to the largest data point less than 1.5 times the box height from the box (the "upper inner fence"), and similarly below the box, outlying values shown as circles, values more than 3 times the box height from the box (the "outer fences") are shown as stars.