Extended Data Fig. 1: Geographic and climatic distribution of vegetation plots.
Distribution of vegetation plots (A) across the globe, and (B) in climate space represented by mean annual temperature (MAT) and mean annual precipitation (MAT) superimposed onto Whittaker biomes78. The legend for color codes of vegetation types (black=forest, gold=grassland, blue=wetland) can be seen in panels C and D. Note the heavy bias toward North America, Europe, and Asia. Plots are located in all major biomes except tropical rainforest, but the majority of plots are found in temperate grasslands, temperate forests and woodlands, and boreal forest biomes. Note that we do not use the Whittaker biomes in our classification of plots into forest, grassland, and wetlands but rather use the composition data to do so (see Methods). These three vegetation types span a broad range of climate space and it is common to find grassland plots in a forest biome and forest plots within a grassland biome. (C) Plots in climate space using the climate variables that were used in the models (minimum temperature of the coldest month, and the precipitation-to-potential evapotranspiration ratio). (D) Principal coordinates analysis (PCoA) of vegetation composition using Bray-Curtis distances. The first axis explains 12% of the variation and the second axis explains 5%. Plots are color-coded according to how they were classified (that is, forest, grassland, wetland) and we illustrate 80% confidence ellipses for each vegetation type. This plot illustrates a random sample of 15,461 plots because analysis of >100,000 observations with >600 species was not computationally feasible within the time limits imposed by high-performance computer clusters.
