Holocene climate aridification trend and human impact interrupted by millennial- and centennial-scale climate fluctuations from a new sedimentary record from Padul (Sierra Nevada, southern Iberian Peninsula)
Holocene centennial-scale paleoenvironmental variability has been described in a multiproxy analysis (i.e., lithology, geochemistry, macrofossil, and microfossil analyses) of a paleoecological record from the Padul Basin in Sierra Nevada, southern Iberian Peninsula. This sequence covers a relevan...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-01-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/14/117/2018/cp-14-117-2018.pdf |
| Summary: | Holocene centennial-scale paleoenvironmental variability has been described
in a multiproxy analysis (i.e., lithology, geochemistry, macrofossil, and
microfossil analyses) of a paleoecological record from the Padul Basin in
Sierra Nevada, southern Iberian Peninsula. This sequence covers a relevant
time interval hitherto unreported in the studies of the Padul sedimentary
sequence. The ∼ 4700-year record has preserved proxies of climate
variability, with vegetation, lake levels, and sedimentological change during
the Holocene in one of the most unique and southernmost wetlands in Europe.
The progressive middle and late Holocene
trend toward arid conditions identified by numerous authors in the western
Mediterranean region, mostly related to a decrease in summer insolation, is
also documented in this record; here it is also superimposed by
centennial-scale variability in humidity. In turn, this record shows
centennial-scale climate oscillations in temperature that correlate with
well-known climatic events during the late Holocene in the western
Mediterranean region, synchronous with variability in solar and atmospheric
dynamics. The multiproxy Padul record first shows a transition from a
relatively humid middle Holocene in the western Mediterranean region to more
aridity from ∼ 4700 to ∼ 2800 cal yr BP. A relatively warm and
humid period occurred between ∼ 2600 and ∼ 1600 cal yr BP,
coinciding with persistent negative North Atlantic Oscillation (NAO)
conditions and the historic Iberian–Roman Humid Period. Enhanced arid
conditions, co-occurring with overall positive NAO conditions and increasing
solar activity, are observed between ∼ 1550 and
∼ 450 cal yr BP (∼ 400 to ∼ 1400 CE) and colder and
warmer conditions occurred during the Dark Ages and Medieval Climate Anomaly
(MCA), respectively. Slightly wetter conditions took place during the end of
the MCA and the first part of the Little Ice Age, which could be related to a
change towards negative NAO conditions and minima in solar activity. Time
series analysis performed from local (<i>Botryococcus</i> and total organic
carbon) and regional (Mediterranean forest) signals helped us determining the
relationship between southern Iberian climate evolution, atmospheric and
oceanic dynamics, and solar activity. Our multiproxy record shows little
evidence of human impact in the area until ∼ 1550 cal yr BP, when
evidence of agriculture and livestock grazing occurs. Therefore, climate is
the main forcing mechanism controlling environmental change in the area until
relatively recently. |
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| ISSN: | 1814-9324 1814-9332 |