Figure 3
From: Humans and climate change drove the Holocene decline of the brown bear
Direct and indirect effects of environmental conditions and human land use on the extinction rate of the brown bear in Europe during the past 12,000 years. (a) Path diagram and (b), direct effects of land use (LU), winter temperature (WT), net primary productivity (NPP), and elevation (ELE) on the extinction rate of the brown bear, as well as indirect effects of the three environmental variables mediated by humans. In (a), paths that emerged from Bayesian variable selection with a probability >95% are highlighted with an asterisk (Supplementary Table 2). Path widths are proportional to standardized effect sizes. In (b), the violins represent the density distributions of estimated direct and indirect effects for each explanatory variable. Note that positive effects (red paths) increase extinction rate, whereas negative effects (blue paths) decrease extinction rate. Uncertainty in model assumptions was incorporated by a two-factorial design with two scenarios for changes in per capita land-use intensity during the Holocene (constant versus decreasing) and two scenarios for colonization of the European continent by the brown bear from Asia (yes versus no), respectively (see Supplementary Methods).
