Fig. 2: Spatial trends of mean tree size and the scale parameter across Amazonian forests.

a,b, Distribution of annual trends of mean tree BA (a) and scale parameter (b) per inventory plot across Amazonia. Trends represent the slope of a linear regression fit to mean tree size and scale parameter within each inventory plot. These vary from −7.1 × 10⁻⁴ to 2.2 × 10⁻³ m² yr⁻¹ and −1.1 to 3.7 yr⁻¹ for mean tree size and scale parameter, respectively. Mean tree size changed on average by 1.45 × 10⁻⁴ m² yr⁻¹ across all plots, 3.3% gain per decade compared to initial mean size of 4.78 × 10⁻² m². The average change in scale parameter was 0.4 yr⁻¹, 3.8% per decade compared to initial mean scale parameter of 103. Arrows show the magnitude and direction of trends at each plot location, with blue arrows showing increasing trends and red arrows showing declining trends.