But due to former dictator Francisco Franco's push towards industrialisation in the mid-20th century, Spain's rural population started to decrease. A lack of labour forced farmers to abandon the ancient trees?most of which are between 100 and 1,000 years old.

Much of Spain is unpopulated due to a phenomenon known as the "Serranía Celtibérica" or the "Spanish Lapland," where vast interior regions have population densities lower than parts of the Sahara. This "demographic desert" is the result of centuries of rural exodus; during the mid-20th century, millions of Spaniards migrated from the arid, agricultural interior to industrial coastal cities like Barcelona and Bilbao, or to the political hub of Madrid. Geographically, the interior "Meseta" plateau suffers from a harsh continental climate—extremely hot summers and freezing winters—and poor soil fertility compared to the fertile Mediterranean coast. Politically, the centralizing focus on Madrid has created a "snowball effect" where investment and infrastructure follow the people, leaving 70% of the land to be occupied by only 10% of the population. This has led to "La España Vaciada" (the Emptied Spain), where thousands of villages are now inhabited only by the elderly or are completely abandoned.