Fig. 4

Impact of factor combinations on the entirety of the relative variation of the biological parameters. a Silver species × soil texture, b exposure time × soil texture. The error bars represent the 95% confidence interval. N = 4320. The relative variations (%) were set as dependent variable. The factors were set as independent variable. To calculate the impact of the factor combination silver species× soil texture on the relative variation of the biological parameters, the relative variations were unconnected to the factors concentration and exposure time (a). To calculate the impact of the factor combination exposure time × soil texture on the relative variation of the biological parameters, the relative variations were unconnected to the factors concentration and silver species (b)