Fig. 2: Modeled temporal and spatial variation in plant group biomass (forbs, graminoids, deciduous shrubs and dwarf shrubs, and crowberry).

a Change in time. Estimates of posterior mean distributions of biomass of forbs, graminoids, deciduous shrubs, and crowberry, separately for each plant group in 2003 (gray) and in 2020 (green colors). Means and 95% confidence intervals from observed data for each year are provided as point intervals at the base of each biomass density plot (note a full overlap for forbs and graminoids). b Association between plant group biomass and the spatial density component. Each point represents a reindeer district, showing the mean and model-derived 95% and 80% credible intervals of the estimated posterior mean distribution. The line represents the linear association across all districts. c Model-derived estimates of the relationship of plant biomass and the (recomposed) reindeer density. Each short solid black line connects averaged model estimates in 2003 and 2020 in each district, and a regression line is fitted with log(density) across all districts. Data in all panels includes 100 draws from the posterior distribution, and the colored regression lines and adjusted R² across all districts are estimated with the package ggpmisc functions stat_poly_line and stat_poly_eq¹¹⁹.