Fig. 4.

Schematic illustration of community composition shift quantification. In panel A, the orange numbers indicate Jaccard’s dissimilarity index values when comparing community composition of a hypothetical focal EBBA1 grid cell (orange outlines, on the left) to hypothetical EBBA2 comparison grid cells (four squares on the right, including the focal grid cell). The gray arrow points from the focal EBBA1 grid cell to the compositionally best-matching EBBA2 grid cell (i.e., smallest dissimilarity value), indicating the spatiotemporal shift of the breeding bird community composition. Panel B illustrates the spatial variation in the observed Jaccard’s dissimilarity index values across the extent of EBBA1 grid cells (N = 2,092), quantified as the dissimilarity between each focal EBBA1 grid cell and its best-matching EBBA2 grid cell.