Ancient oaks reveal rewilding of Mediterranean forests after the Black Death

Abstract

In Italy, evergreen holm oaks ( Quercus ilex ) and deciduous sessile oaks ( Quercus petraea ) experienced a synchronized establishment pulse starting at the beginning of 1400s CE, consistent with a release from anthropogenic pressure following demographic collapse associated with the Black Death outbreak (1347 CE) and its following waves until the 17th century. Radiocarbon dating of the oldest-looking individuals of each species revealed similar tree-age distributions across sites located at the extremes of the forest elevational gradient: Montecristo Island (100 to 500 m a.s.l.) and Aspromonte mountain (1,100 to 1,800 m a.s.l.). Montecristo, with its favorable coastal conditions, showed a pronounced post-1400 CE recruitment peak, while the mountainous Aspromonte region, at harsher high elevations, required a more extended and delayed period of recruitment. The extreme longevity of these two unrelated oak populations is enabled by different functional traits and resilience mechanisms, highlighting an ancient rewilding event spurred by human tragedy.