Fig. 3: Regression model linking climate / land-use changes and species traits to short-term species trends.

a Schematic model representation. The response variable was 5-year species trends of regional mean occupancy (n_tot =  20,048). Explanatory variables included changes in climate (annual mean temperature, temperature seasonality, summer precipitation) and land use (total agricultural area, grassland-use intensity, crop-use intensity), two trait variables, elevation (low or high) and interactions (indicated with ×) (cf. Fig. 1). In the restricted model version underlying the results presented in panel (b), parameter estimates for change in total agricultural area and grassland-use intensity (in italic) were only based on species of agriculturally influenced habitats (183 butterfly species, 93 grasshopper species; n = 13,968). Non-independence within insect groups, time intervals, bioclimatic zones and species was accounted for. b Model results along the same arrangement as in (a). Curves show posterior distributions of model estimates; fill colours indicating effect sizes (positive values in blue, negative values red); dashed vertical lines indicate zero; numbers are posterior distribution means. Two-way interactions of change and trait variables with elevation are included such that upwards-facing curves show model estimates for high elevation and downwards-facing curves for low elevation (too low amounts of crop fields at high elevation to include interaction with crop-use intensity). Overlapping areas show other two-way interactions. The bottom centre panel shows how to interpret effect sizes. Starting at the overall mean occupancy, expected mean occupancy changes in 5 years when an explanatory variable is increased by one standard deviation are shown. All explanatory variables were standardised prior to analysis.