Fig. 4: Decrease in diazotrophic community relative richness under future climate scenarios.
From: Anthropogenic climate change may reduce global diazotroph diversity
a Trends in the relative richness of diazotrophs under future climate scenarios (2080–2100). The prediction model was based on current bioclimatic variables (resolution of 0.083°) and constructed by the random forest algorithm (Supplementary Fig. 10). The model was used to predict the relative richness of potential future nitrogen-fixing organisms under four climate scenarios for different carbon emission societies (SSP: shared socioeconomic pathway; SSP126: sustainability; SSP245: middle of the road; SSP370: regional rivalry; SSP585: fossil-fuelled development), and we averaged the predictions of downscaled global change models (GCMs; n = 14 for SSP126; n = 12 for SSP245 and SSP585; n = 11 for SSP370) under the same climate scenarios and calculated their changes relative to the current climate (Supplementary Fig. 11). b Overall change in the relative richness of diazotrophs across latitudes under different climate scenarios. We calculated the mean changes in relative richness and showed trends by latitude. c Changes in relative richness across continents under different climate scenarios. We show overall changes in relative richness compared with the current values in all GCMs for each climate scenario based on different intercontinental divisions. For the box plots, the middle line indicates the median, the box represents the 25th (Q1) and 75th (Q3) percentiles (box boundaries), and the whiskers indicate the Q1 − 1.5 IQR and Q3 + 1.5 IQR of the observations. d Proportion of area occupied by each continent whose relative richness changed under different climate scenarios. The bar plot shows the proportions of relative changes in area based on different intercontinental divisions (e.g., the proportions of relative decreases in area are defined as the ratio of the number of pixels in the decreased region to the overall number of pixels). The colour indicates the direction of change for relative richness (increases or decreases). Source data are provided as a Source Data file.
