Figure 2 Radar maps of biodiversity under N addition rates in
ICNs (left panel) and TCNs (right panel) from 2008 to 2020. The radius
is a measure of biodiversity, and the N addition rate is expressed in
shades of colour from red (0 g N m-2year-1) to blue (50 g N m-2year-1). The points represent the average number of
species under different N addition rates in each year. The value zero
means that the diversity at this time was no longer regulated by the
network structure.