Schematic representation of the primary causes of woody plant expansion in European alpine ecosystems. The decrease in mountain rural populations causes a decline in agropastoral activities and therefore a reduction in livestock densities. At the same time, temperatures increase due to climate change. The combination of these factors leads to the expansion of woody plants in alpine grasslands (1. Gartzia et al., 2016; 2. Didier, 2001; 3. Metailié & Paegelow, 2005; 4. Lasanta-Martínez et al., 2005; 5. Collantes, 2006; 6. Sturaro, Cocca, Fuser, & Ramanzin, 2005; 7. Büntgen, Frank, Nievergelt, & Esper, 2006; 8. Büntgen et al., 2017; 9. Cannone, Sgorbati, & Guglielmin, 2007; 10. Roura-Pascual, Pons, Etienne, & Lambert, 2005; 11. Bartolomé et al., 2005; 12. Kozak, Estreguil, & Troll, 2007)