Extended Data Fig. 4: Effect of plot surface area on plant diversity change.
From: More losses than gains during one century of plant biodiversity change in Germany
The temporal change of species richness (SR) in plot records (a–c) and mean cover change of species (d–f) is shown shown separately for small (> 25 m2), medium-size (25 m2) and large plots (>25 m2). The black dashed line shows zero change, while the red solid line in a)–c) shows the mean change of richness and in d)–f) the species’ median change in cover in percentage points. According to a mixed effects model estimated mean overall effect size was in a) −0.03 (p = 0.064, df = 487), b) −0.031 (p = 1.55 x 10−13, df = 4,204) and c) −0.095 (p < 2 x 10−16, df = 9,124). In d)–f) plot Interval comparisons of the mean of all cover changes per species between time points Y1 and Y2 of the start and end year, respectively, are shown on an axis with a sign*square root-transformation. According to an exact binomial test estimated overall median of cover change was in d) −0.017 (95 per cent confidence interval −0.065 and −0.001), e) −0.019 (CI −0.043 and −0.006) and f) −0.26 (CI −0.134 and −0.050).
