Paleosol charcoal: 12,700 years of high-altitude mediterranean vegetation history in relation to forest fires in the southwestern baetic cordillera (Spain)

Abstract

Mountain forests are sensitive ecosystems. This is why in recent years the dynamics of these forest ecotones have been researched from several different approaches. One of these has been the paleoecological perspective, which is particularly interesting in the mountainous areas of the Mediterranean region, where interactions between climate, vegetation and anthropic activities have been documented for millennia. This is the case of the Sierra de las Nieves Natural Park (southwestern Baetic Cordillera), a mountainous area that constitutes an important refuge for flora in southern Iberian Peninsula. At present, endemic trees such as Abies pinsapo and Quercus faginea subs. alpestris are found. However, its strategic geographical location may also have served in the past as a refuge for other tree taxa. In order to reconstruct the vegetation history in this protected natural area, this research aims to use pedoanthracological analysis in an unexplored area of this mountainous system. The results obtained have allowed to identify a new paleopopulation of Abies, a finding that provides new keys on the paleobiogeography of this species. This is the oldest evidence of this genus and at the highest altitude of those found to date in the southwestern Baetic Cordillera, which would confirm that this fir tree was present in high elevations of the Sierra de las Nieves during the Pleistocene-Holocene transition. Likewise, the first anthracological evidence of Pinus nigra/sylvestris type in the southwestern end of the Baetic Cordillera has been obtained. Forest fires could have been one of the main factors which would be determined the shaping and evolution of the vegetation landscape, as suggested by the fire events identified from the soil analysis. This information can be useful for the conservation and adaptive management of the most threatened forests and their habitats in the face of global change.