Fig. 4

Results of variance partitioning for different drivers (i.e., land use and water quality) of P-IBI in the middle and lower reaches of the Yangtze River in 2017–2018 for a the wet season and b the dry season. Values in the circles indicate the amount of variation in P-IBI explained independently or jointly by land use and water quality parameters. All scores (*P < 0.05) are based on adjusted R² values, with residuals shown below and negative values not shown