Fig. 2From: Changing soil carbon: influencing factors, sequestration strategy and research directionChanges in soil C due to the effects of each factor. The circles and error bars represent the means and 95% confidence intervals; the numbers next to the Y axes indicate the number of observations and studies. The results are significant at p < 0.05 (*), p < 0.01 (**), and p < 0.001 (***)Back to article page