Holocene changes in precipitation seasonality in the western Mediterranean Basin: a multi‐species approach using δ¹³C of archaeobotanical remains

Abstract

Precipitation has been of utmost importance in shaping the evolution of landscapes and human settlements in the Mediterranean. However, information on seasonal precipitation patterns through the Holocene is scarce. This study attempts to quantify the evolution of seasonal precipitation in the East Iberian Peninsula (5000 BC to AD 600) based on the carbon isotope composition (d 13 C) of archaeobotanical remains. Data on Holm oak, Aleppo pine and small-grain cereals were combined, and precipitation was inferred from models relating present-day records to the d 13 C of modern samples. Subsequently, charred grains were used as a proxy for ancient moisture during AprilMay, whereas oak and pine charcoals provided complementary rainfall estimates for September-December and January-August, respectively. The results reveal aridity changes throughout the Holocene in the western Mediterranean. Past spring-summer precipitation was consistently higher than at present. In contrast, autumn and early winter precipitation showed stronger fluctuations, particularly during the first millennium BC, and often exhibited values below those of the present. The high contribution of autumn precipitation to the annual water budget, typical of the present Mediterranean climate, was definitively established at the beginning of the current era. This study shows how a combination of species holding complementary environmental signals can contribute to a wider knowledge of local precipitation dynamics.

Three millennia of heavy rainfalls in Western Mediterranean: frequency, seasonality and atmospheric drivers

“…This increase likely resulted in greater water availability in the Iberian Peninsula during the Iberian and Roman period with a concomitant reduction in summer precipitation. Our results corroborate a previous hypothesis suggesting wetter winters with drier summers in the Ebro basin between 900–300 BCE29 and a large increase is autumn precipitation between BCE 400 and CE 100 in Western Mediterranean, based on 13 C analyses in fossil charcoal remains30.…”

Isoscapes of tree‐ring carbon‐13 perform like meteorological networks in predicting regional precipitation patterns

“…halepensis Mill.) were compiled from previous studies [ Aguilera et al ., ; ; Ferrio et al ., ; Ferrio and Voltas , ]. Altogether, we used 44 sampling locations for Q .…”

“…halepensis and Q . ilex , which are known to provide complementary information on seasonal precipitation [ Aguilera et al ., ; Ferrio et al ., ]. After comparing the performance of isoscape‐derived spatial models with those derived from meteorological records, the potential and limitations for modeling spatial variability in precipitation from tree‐ring isotope networks are discussed.…”

Wild fruit use among early farmers in the Neolithic (5400–2300 cal bc) in the north-east of the Iberian Peninsula: an intensive practice?

“…Maquis vegetation increased its significance towards the 4th and 3rd millennia cal BC (Riera Mora 2006;Riera et al 2007). Recently, isotopic analyses identified one particularly drier phase between 4000 and 3000 BC (Aguilera et al 2012). The available data support a progressive climatic aridification during the middle Neolithic period (Pérez-Obiol et al 2011; see a more extensive compilation of literature in Antolín 2013).…”