Fig. 3: Identification of the relevant spatial extent to measure deforestation impact on biodiversity.

Left panels indicate variance explained by mixed models (R²) for each spatial extent. Right panels indicate the strength of deforestation effect on biodiversity (slopes). Spatial extents account for deforested areas upstream from eDNA sampling sites. a, b Fish species richness (SR) models. c, d Fish functional richness (FR) models. e, f Mammal species richness models. g, h Mammal functional richness models. For each spatial extent, a specific generalized linear mixed model accounting for site network position and basin identity as random effects was built for each biodiversity facet. Significant (p < 0.05) and non-significant (p > 0.05) models assessed with Wald’s tests are indicated by filled and open circles, respectively (Supplementary Table 1). Fish: n = 64 sites and mammals: n = 74. Colour shades are consistent with spatial extents. Grey vertical bars indicate models with highest R² or R² reaching a plateau, with less than 5% variation between successive spatial extents.