Millennial-scale cyclical environment and climate variability during the Holocene in the western Mediterranean region deduced from a new multi-proxy analysis from the Padul record (Sierra Nevada, Spain)

Ramos-Román, M. J. et al. (2018) Millennial-scale cyclical environment and climate variability during the Holocene in the western Mediterranean region deduced from a new multi-proxy analysis from the Padul record (Sierra Nevada, Spain). Global and Planetary Change, 168, pp. 35-53. (doi: 10.1016/j.gloplacha.2018.06.003)

Abstract

A high-resolution multi-proxy approach, integrating pollen, inorganic and organic geochemical and sedimentological analyses, has been carried out on the Holocene section of the Padul sedimentary record in the southern Iberian Peninsula reconstructing vegetation, environment and climate throughout the last ~ 11.6 cal kyr BP in the western Mediterranean. The study of the entire Holocene allows us to determine the significant climate shift that occurred during the middle-to-late Holocene transition. The highest occurrence of deciduous forest in the Padul area from ~ 9.5 to 7.6 cal kyr BP represents the Holocene humidity optimum probably due to enhanced winter precipitation during a phase of highest seasonal anomaly and maximum summer insolation. Locally, insolation maxima induced high evaporation, counterbalancing the effect of relatively high precipitation, and triggered very low water table in Padul and the deposition of peat sediments. A transitional environmental change towards more regional aridity occurred from ~ 7.6 to 4.7 cal kyr BP and then aridification enhanced in the late Holocene most likely related to decreasing summer insolation. This translated into higher water levels and a sedimentary change at ~ 4.7 cal kyr BP in the Padul wetland, probably related to reduced evaporation during summer in response to decreased in seasonality. Millennial-scale variability is superimposed on the Holocene long-term trends. The Mediterranean forest regional climate proxy studied here shows significant cold-arid events around ~ 9.6, 8.5, 7.5, 6.5 and 5.4 cal kyr BP with cyclical periodicities (~1100 and 2100 yr) during the early and middle Holocene. A change is observed in the periodicity of these cold-arid events towards ~1430 yr in the late Holocene, with forest declines around ~ 4.7–4, 2.7 and 1.3 cal kyr BP. The comparison between the Padul-15-05 data with published North Atlantic and Mediterranean paleoclimate records suggests common triggers for the observed climate variability, with the early and middle Holocene forest declines at least partially controlled by external forcing (i.e. solar activity) and the late Holocene variability associated with internal mechanisms (oceanic-atmospheric).

• Item Type: Articles
• Additional Information: This work was supported by the project P11-RNM-7332 funded by Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía, the project CGL2013-47038-R funded by Ministerio de Economía y Competitividad of Spain and fondo Europeo de desarrollo regional FEDER and the research group RNM0190 (Junta de Andalucía). M. J. R.-R. acknowledges the predoctoral and postdoctoral funding provided by Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía (P11-RNM-7332). J.C. acknowledges the PhD funding provided by Ministerio de Economía y Competitividad (CGL2013-47038-R). J.S.C. acknowledges the support of projects CGL-BOS-2012-34717, CGL-BOS 2015-68604, and Fundación Séneca 19434/PI/14. A.G.-A. was also supported by a Ramón y Cajal Fellowship RYC-2015-18966 of the Spanish Government (Ministerio de Economía y Competividad).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Garcia-Alix Daroca, Dr Antonio and Toney, Professor Jaime
• Authors: Ramos-Román, M. J., Jimenez-Moreno, G., Bidaurreta, J. C., Garcia-Alix, A., Anderson, R. S., Jimenez-Espejo, F. J., Sachse, D., Toney, J., Carrión, J., Webster, C., and Yanes, Y.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Global and Planetary Change
• Publisher: Elsevier
• ISSN: 0921-8181
• ISSN (Online): 1872-6364
• Published Online: 08 June 2018
• Copyright Holders: Copyright © 2018 Elsevier
• First Published: First published in Global and Planetary Change 168:35-53
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher