Extended Data Fig. 5: Pairwise correlations between different environmental variables and tree species diversity.
From: Boreal tree species diversity increases with global warming but is reversed by extremes
for a, 2000, b, 2010, and c, 2020. The color gradient of the legends indicates Pearson’s correlation coefficient, with more positive/negative values (dark blue/red) indicating stronger positive/negative correlations. Asterisks ‘*’ denote the significance levels of the Pearson’s correlation coefficients based on two-sided t-tests: *** p < 0.001, ** p < 0.01, * p < 0.05. D_2000: H′ values in 2000, D_2010: H′ values in 2010, D_2020: H′ values in 2020, TMP_2000: mean seasonal temperature in 2000; PR_2000: mean seasonal precipitation in 2000; Fire_2000: fire activity frequency in 2000; POP_2000: human population density in 2000; TMP_2010: mean seasonal temperature in 2010; PR_2010: mean seasonal precipitation in 2010; Fire_2010: fire activity frequency in 2010; POP_2010: human population density in 2010; TMP_2020: mean seasonal temperature in 2020; PR_2020: mean seasonal precipitation in 2020; Fire_2020: fire activity frequency in 2020; POP_2020: human population density in 2020; S_OC: topsoil organic carbon; S_SAND: topsoil sand fraction; S_CEC: cation exchange capacity; DEM: Digital Elevation Model.
