Points show coefficients from model-averaged linear models, n = 123 plots, and error bars show 95% CIs, centred on the mean. Variables that did not occur in well-supported models are shrinkage adjusted towards zero. Coefficients are standardized so that they represent change in the response variable for one standard deviation change in the explanatory variable. The full models explained 18%, 31% and 12% of variation in net carbon, carbon gains and carbon losses. Equations for models are listed in Supplementary Table 2 . See Extended Data Fig. 8 for an alternative analysis excluding censuses before 2000, and Extended Data Fig. 9 for an alternative analysis with carbon changes in absolute terms.
