Extended Data Fig. 7: Relationship between changes in NDVI/tree cover and H′ based on a multiple linear regression model.
From: Boreal tree species diversity increases with global warming but is reversed by extremes
Seasonal mean (May−October) NDVI for 2000 (NDVI_2000) and 2020 (NDVI_2020) obtained from the Landsat-7 and Landsat-8 satellites. The tree cover data for 2000 (TC_2000) and 2020 (TC_2020) were obtained from Hansen et al.6 and the Copernicus Global Land Service (Buchhorn et al. 2019). Changes in greenness and tree cover were calculated from the differences between NDVI_2020 and NDVI_2000, TC_2020 and TC_2000, respectively, and were used as explanatory variables. The β and R² marked in black were calculated using the in situ H′ as the response variable, while those in grey were calculated using the predicted H′ as the response variable. Both NDVI and tree cover were standardised prior to the linear regression analysis. The plots with repeated measurements of H′ derived from the forest inventory dataset were used for this analysis (n = 648).
