Rapid climatic variability in the west Mediterranean during the last 25 000 years from high resolution pollen data

Abstract

Abstract. High-temporal resolution pollen record from the Alboran Sea ODP Site 976, pollen-based quantitative climate reconstruction and biomisation show that changes of Mediterranean vegetation have been clearly modulated by short and long term variability during the last 25 000 years. The reliability of the quantitative climate reconstruction from marine pollen spectra has been tested using 22 marine core-top samples from the Mediterranean. The ODP Site 976 pollen record and climatic reconstruction confirm that Mediterranean environments have a rapid response to the climatic fluctuations during the last Termination. The western Mediterranean vegetation response appears nearly synchronous with North Atlantic variability during the last deglaciation as well as during the Holocene. High-resolution analyses of the ODP Site 976 pollen record show a cooling trend during the Bölling/Allerød period. In addition, this period is marked by two warm episodes bracketing a cooling event that represent the Bölling-Older Dryas-Allerød succession. During the Holocene, recurrent declines of the forest cover over the Alboran Sea borderlands indicate climate events that correlate well with several events of increased Mediterranean dryness observed on the continent and with Mediterranean Sea cooling episodes detected by alkenonebased sea surface temperature reconstructions. These events clearly reflect the response of the Mediterranean vegetation to the North Atlantic Holocene cold events.

Vegetation dynamics in the Northeastern Mediterranean region during the past 23 000 yr: insights from a new pollen record from the Sea of Marmara

“…5) similarly to what was already described in Western Mediterranean Fletcher et al, 2010b), suggesting a warming trend from the Bölling towards the Allerød. Our findings then support the idea of a climatic contrast during B/A, with Greenland and North Europe experiencing a cooling trend towards the end of the B/A while climate stability or warming was evidenced in Southern Europe (Genty et al, 2006;Combourieu-Nebout et al, 2009).…”

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)

“…Humid climate conditions at around 2500 cal yr BP are also interpreted in previous studies from lake level reconstructions from central Europe (Magny, 2004). Increases in temperate deciduous forest are also observed in marine records from the Alboran Sea around 2600 to 2300 cal yr BP, also pointing to high relative humidity (Combourieu Nebout et al, 2009). Overall humid conditions between 2600 and 1600 cal yr BP seem to agree with predominant negative NAO reconstructions at that time, which would translate into greater winter (and thus more effective) precipitation in the area, triggering greater development of forest species in the area.…”

Environmental Drivers of Holocene Forest Development in the Middle Atlas, Morocco

“…More widely, an important role of Early Holocene high summer temperatures is implicated in strong development of evergreen Quercus in the Alboran Sea basin regions of S Iberia and N Morocco (Fletcher and Goñi, 2008;Combourieu Nebout et al, 2009) and southern Portugal (Fletcher et al, 2007). High temperatures during the Early Holocene are also implicated in the maximum depletion in speleothem 13 C by 9,500 cal yr BP at La Mine Cave in Tunisia associated with enhanced soil microbial activity above the cave (Genty et al, 2006).…”