The speed of change in climate and land cover is associated with the speed of biodiversity changes in avian assemblages of the United States

PLOS One | https://doi.org/10.1371/journal.pone.0330153 August 29, 2025 7 / 20 Forested Mountains; Table 2, S5B, S5E Fig in S1 File) and to rapid warming of the minimum temperature (Northwestern Forested Mountains; Table 2, S5I Fig in S1 File). For Great Plains and North American Deserts, our models did not detect an association between rate of change in species richness and rate of change in environmental variables (Table 2). Predictive power of dissimilarity models and species richness models across geographical scales. We present values of the amount of variance in the biodiversity metrics explained by the environmental predictors (R2) for each model and resolution in Table 3. There was some variability in predictive power of the different models. The predictive power of the models of species richness was consistently lower than that of the models for total assem- blage dissimilarity (Table 3). Further, more environmental predictors were significantly associated with the rate of change of total assemblage dissimilarity than of species richness, with the exception of the model of species richness in the Northwestern Forested Mountains (Tables 1 and 2). In comparison to the aforementioned models, the predictive power of Table 1. GAMMs relating the rate of change of assemblage dissimilarity metrics with the rate of change of the environment in five ecoregions of the US at a resolution of 25 km (1990–2019). Ecoregion Biodiversity metric PPT (mm) Tmax (oC) Tmin (oC) Barren land Crop/ Pasture Forest Grassland/ Shrubland Urban Wetland Elevation (m) R2 Northern Forest

(N = 61) Total dissimilarity – (-) – (**) – (-) NA – (-) −2.9* (*) −3.2* (*) – (-) −4.7** (**) – (-) 0.33 Species replacement – (-) – (-) – (-) NA – (-) – (-) – (-) −3.4^ (*) – (-) – (-) 0.07 Species loss – (-) – (-) – (-) NA – (-) – (-) −2.9** (**) – (-) −4.8*** (***) – (-) 0.30 North- western Forested Mountains (N = 56) Total dissimilarity −6.7*** (***) – (-) 3.3* (*) 3.3* (*) 3.6* (*) 4* (*) – (-) NA – (-) NA 0.27 Species replacement −6.8** (**) – (-) −35** (***) – (-) 5* (***) – (***) −3* (**) NA – (-) NA 0 Species loss No term was significant 0 Great Plains (N = 95) Total dissimilarity – (-) – (-) – (-) NA NA NA – (-) – (-) – (-) – (*) 0.07 Species replacement – (-) – (-) – (-) NA NA NA – (-) – (-) −3.5* (*) – (-) 0.02 Species loss – (-) – (-) – (-) NA NA NA – (-) – (-) 2.6* (*) −2.2* (*) 0.12 North American Deserts (N = 50) Total dissimilarity No term was significant 0.06 Species replacement – (-) NA – (-) – (-) – (-) – (*) – (-) NA NA 5* (*) 0.10 Species loss – (-) NA – (-) −3.6* (*) – (-) – (-) – (-) NA NA −3.1^ (*) 0.13 Eastern Temperate Forest (N = 309) Total dissimilarity – (-) – (-) – (-) NA – (-) – (-) – (-) NA – (-) −2.7*** (***) 0.08 Species replacement −2.4** (**) – (-) – (-) NA – (-) – (-) – (-) NA – (-) −1.9** (**) 0.04 Species loss 2.1* (*) – (-) – (-) NA – (-) – (-) – (-) NA – (-) – (-) 0.04 We show the linear model coefficients of variables with a significant effect and the significance of smooth terms between parenthesis for all variables.

Linear model coefficients are on the scale of x10-4. We also present the proportion of the variability the model explains (Adjusted R2) and the number of BBS routes included in the analyses (N). Significant P-values are represented as follow: ***P < 0.001, **P < 0.01, *P < 0.05. Marginally significant P-values are represented as ^P < 0.065. Non-significant effects are denoted with a single dash (-) and predictor variables not included in the model are denoted with NA. https://doi.org/10.1371/journal.pone.0330153.t001