Fig. 2.

Modeled relationships between ecological barriers and community composition shifts. Predicted linear effects of the three barriers on community composition shift distances (number of grid cells shifted, A–D) and directions (E–L) based on full models. Linear regressions of full model predictions are plotted for all barrier variables by using the term of interest and averaging over other terms in the model. Note that temperature isotherm shift and initial dissimilarity were present as fixed effects in all models. Regression lines are model-based beta estimates, where solid regression lines show significant (P < 0.05) and dashed lines (P > 0.05) near- or nonsignificant relationships. Shaded areas are the 95% CI, and raw data distributions are illustrated at the top and right-hand side axes. Stacked bar plots D, H, and L illustrate the relative variable importance per model (rounded). Note that directions of response and predictor variables range from −1 to 1 as they were sine and cosine transformed to obtain linear expressions along the west–east (E) and south–north (N) axes, respectively. N = 2,092 for A–D (shift distance) and N = 1,407 for E–L (shift direction). BG dissimilarity = initial background dissimilarity.