Figure 3

Change points of the aggregated sum(z−) and sum(z+) values for pooled richness, the species groups and tree-related microhabitats. These change points indicate where, along the gradients, species increase (positive, blue triangle) or decrease (negative change point, red square) their frequency. If symbols are missing, the respective group did not show a reliable negative or positive change along the gradient. Evidence for community-level thresholds among negative and positive taxa is assessed separately by tabulating and summing all negative change points (z−) and positive change points (z+) scores³⁹. Sharp, nonlinear responses in taxon richness are reflected by relatively narrow intervals between upper and lower change point quantiles (5%, 95%), indicated by shorter whiskers. In cases where a species group shows a linear or more gradual response, they have broad whiskers spanning most of the range of the predictor. This graph was produced in R using the TITAN2 package³⁹.