Extended Data Fig. 6: Temporal trends in planktonic (a, n = 296) and oceanic (b, n = 59929) ecological stoichiometry of the Arctic Ocean.

The boxplot represents the distribution of data for all years from 1970 to 2020. For the boxplot, the straight line in the center represents the median, or 2nd quartile (Q2), the top edge of the box represents the 3rd quartile (Q3), and the bottom edge of the box represents the 1st quartile (Q1). The black and blue dashed lines represent the Redfield ratio and the ecological stoichiometric ratio established in this study, respectively. The error bars represent the mean and standard deviation of the stoichiometric ratios for each year. The significance of the non-zero coefficients in the segmented model fitting is evaluated through a two-tailed t-test. If p > 0.05, it indicates that there is no obvious trend of change in the stoichiometric ratio over time. The shaded area of the fitted line represents the 95% confidence interval of the predicted values. The shaded area at the segmentation point represents the uncertainty of the time breakpoints, which is derived from the standard deviation of the breakpoint estimates across iterations based on resampling. *, p < 0.05; **, p < 0.01; ***, p < 0.001.