Extended Data Table 4 Explanatory variables for species richness changes

From: Accelerated increase in plant species richness on mountain summits is linked to warming

  1. Linear mixed effects models (Gaussian family error distribution) showing the direct relationship between species richness changes and changes in potential explanatory variables (temperature, precipitation, nitrogen deposition). Initial species richness on the summit was not added as a further independent variable as it did not show significant effects in any of the models. The implemented model formula was lmer(ΔSR ~ ΔT + ΔP + Naccum + richness + (1|mountain)). Variable performance was compared using AICc, which also sets the order of models, with the best one on top. Additional significance tests using F statistics are indicated by asterisks (*P < 0.05, **P < 0.01, ***P < 0.001; P values > 0.001 are additionally reported in brackets). All values indicate model coefficients ± s.e. Rerunning the analyses after centring (subtracting the means) and scaling (dividing by standard deviations) indicated a larger coefficient and thus stronger effect of temperature compared to that of precipitation (ΔSR ~ 0.05 (± 0.06) + 0.25 (± 0.05) × ΔT*** + 0.05 (± 0.05) × ΔP − 0.11 (± 0.05) × Naccum*). The analyses were performed with the same data as specified in Extended Data Table 3.
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