Dry and wet periods over the last millennium in central-eastern Spain - a paleolimnological perspective

Abstract

Dry and wet periods over the last millennium in central-eastern Spain-a paleolimnological perspectiveA compilation of sedimentological, chemical and mainly biological proxies from sedimentary records in three lacustrine systems (La Cruz, El Lagunillo del Tejo and El Tobar) in the Iberian Range provides a synthetic view of hydroclimatic variability in central-eastern Spain during the last millennium. A quantitative rainfall reconstruction from varved sediments in Lake La Cruz was used to calibrate the sedimentary inputs of five biological proxies (photosynthetic pigments, diatoms, cladoceran sub-fossils, plant macrofossils and stable isotopes in authigenic carbonates) in the longer sequence of the nearby Lagunillo del Tejo. In spite of the resolution and the distinct responses of the proxies analysed, the three reconstructions are internally coherent and consistent with available North Atlantic Oscillation reconstructions. The Medieval Climate Anomaly (MCA; AD 900-1300) was marked by changes in humidity but it was generally wet, which contrasts with some reconstructions for Iberia and offers interesting information about the spatial heterogeneity of this period in the region. A drier period (AD 1300-1400) occurred at the onset of the Little Ice Age (LIA; AD 1300-1850), which was generally marked by increasing precipitation. The 20 th century generally records higher humidity except from the beginning of the century. The recovery of longer and higher resolution lake sediments in this key region offers exceptional scientific opportunities for climate research.

Climatic Fluctuations Over the Holocene in Southern Iberia (Sierra Nevada, Spain) Reconstructed by Fossil Cladocerans

“…15 km from the study site). Total annual rainfall is 725 ± 25 mm, most of the precipitation (75%) falls as snow between October and May (AEMET, 2020;IEcolab, 2020) and it is mostly controlled by the North Atlantic Oscillation (NAO) (García-Alix et al, 2017;Ramos-Román et al, 2016) as also shown in other places in Iberia (López-Blanco et al, 2016b;López-Blanco and Romero-Viana, 2019).…”

“…García-Girón et al (2018) investigated the relationship between contemporary and subfossil cladoceran using surface sediments from 25 flatland ponds in the Iberian Plateau to find suitable indicators to track ecological changes over time. López-Blanco et al (2013) also analysed biases between contemporary and fossilized cladocerans from sediments in a karstic sinkhole in the Iberian Ranges and inferred rainfall oscillations during the last millennium (López-Blanco et al, 2012;López-Blanco and Romero-Viana, 2019;Romero-Viana et al, 2009). Cladoceran subfossils were also used in central Spain (Lake El Tobar, Iberian Ranges) as indicators of anthropogenic impacts that involved changes in nutrients and species colonization in the last decades (López-Blanco et al, 2016a.…”