evidence: The experience of rural depopulation and subsequent environmental change in Spain offers insights into the futures of other countries. During the last 70 years, the Pyrenees mountain range of Spain has experienced high rates of depopulation, so severe that at times this phenomenon was referred to as "social desertification" [2021–22]. While Spain has an overall density of 79 people/km2, the Pyrenean districts of Aragon have an average density of 6 people/km2 [23]. Similarly, the Pallars Sobirà District experienced a reduction in population from 12,972 inhabitants in 1900 to 5,049 in 1991. There has also been an altitudinal relocation of the population from mountainous areas to valley bottoms [24]. For example, there has been a fundamental change in the percentage of population living in towns and villages in this district under 1000 m from 36% in 1900 to 60% in 1991 [25]; Fig. 4). These demographic changes have lead to environmental change, as it is the disappearance of human pressure that allows forest expansion [21, 26]. Roura-Pascual et al. [27] quantified increases in forest cover in municipalities of the French Catalan Pyrenees from 32% of the area in 1953, to 52% in 2000.