Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record

Fletcher, William J.; Goñi, María Fernanda Sánchez; Peyron, Odile; Dormoy, Isabelle

doi:10.5194/cp-6-245-2010

Cited by 159 publications

(104 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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).…”

Section: Vegetation Dynamics Inferred From the Pollen Analysissupporting

confidence: 66%

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

2012

Self Cite

View full text Add to dashboard Cite

Abstract. High-resolution pollen analysis of core MD01-2430 from the Sea of Marmara (40 • 47.81 N, 27 • 43.51 E) allows us to reconstruct the vegetation response to climatic changes during the past 23 cal ka in the Northeastern Mediterranean. Variation in mesic/temperate forest cover indicates major climatic shifts connected to Heinrich Stadial 1, Bölling-Allerød, Younger Dryas and to the onset of the Holocene. Pollen-anthropogenic indicator approach was used to recognize human-induced landscape changes in the Sea of Marmara. The pollen-inferred onset of the Holocene occurs at ca. 11.5 cal ka, indicating that the Northeastern Mediterranean region represents a transitional zone where higher moisture availability supported an earlier forest expansion than the borderlands of the Aegean Sea and Black Sea. Two major forest retreats occurred during the Holocene at ca. 5.5 and 2.1 cal ka. The Holocene forest setbacks are in phase with previously published alkenone-inferred seasurface temperature decreases in the Sea of Marmara reconstructed from the same core. Our new pollen record testifies the sensitivity of Mediterranean forests to changes in moisture availability, which is driven by changes in highlatitude atmospheric processes (North Atlantic Oscillations and/or Siberian High).

show abstract

Section: Vegetation Dynamics Inferred From the Pollen Analysissupporting

confidence: 66%

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

2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…8; e.g. Combourieu-Nebout et al, 2009;Schmiedl et al, 2010;Fletcher et al, 2010Fletcher et al, , 2012Desprat et al, 2013) and may be linked to the millennial-scale cold events recorded in the North Atlantic (Bond et al, 1997(Bond et al, , 2001Kotthoff et al, 2008a;Combourieu-Nebout et al, 2009;Schmiedl et al, 2010;Fletcher et al, 2010Fletcher et al, , 2012Fletcher and Zielhofer, 2011;Desprat et al, 2013. The rapid response of the central Mediterranean to millennial-scale variability confirms the influence of midlatitude atmospheric circulation in propagating changes, depending on insolation and ice sheet volume (Desprat et al, 2013).…”

Section: Temperature Patternmentioning

confidence: 67%

“…This steppic vegetation is recorded in numerous regional pollen records (e.g. Watts et al, 1996;Magri and Sadori, 1999;Denèfle et al, 2000;Allen et al, 2002;Bordon et al, 2009;Kotthoff et al, 2011;Combourieu-Nebout et al, 2009;Fletcher et al, 2010;Desprat et al, 2013). Steppic pollen taxa indicate that coldarid climate conditions prevailed over the whole Mediterranean Basin and especially in the Adriatic Basin during the Younger Dryas (Figs.…”

Section: Vegetation and Climate For Core MD 90-917mentioning

confidence: 99%

Holocene vegetation and climate changes in the central Mediterranean inferred from a high-resolution marine pollen record (Adriatic Sea)

et al. 2013

Self Cite

View full text Add to dashboard Cite

The high-resolution multiproxy study of the Adriatic marine core MD 90-917 provides new insights to reconstruct vegetation and regional climate changes over the southcentral Mediterranean during the Younger Dryas (YD) and Holocene. Pollen records show the rapid forest colonization of the Italian and Balkan borderlands and the gradual installation of the Mediterranean association during the Holocene. Quantitative estimates based on pollen data provide Holocene precipitations and temperatures in the Adriatic Sea using a multi-method approach. Clay mineral ratios from the same core reflect the relative contributions of riverine (illite and smectite) and eolian (kaolinite) contributions to the site, and thus act as an additional proxy with which to evaluate precipitation changes in the Holocene. Vegetation climate reconstructions show the response to the Preboreal oscillation (PBO), most likely driven by changes in temperature and seasonal precipitation, which is linked to increasing river inputs from Adriatic rivers recorded by increase in clay mineral contribution to marine sediments. Pollen-inferred temperature declines during the early-mid Holocene, then increases during the mid-late Holocene, similar to southwestern Mediterranean climatic patterns during the Holocene. Several short vegetation and climatic events appear in the record, indicating the sensitivity of vegetation in the region to millennial-scale variability. Reconstructed summer precipitation shows a regional maximum (170-200 mm) between 8000 and 7000 similar to the general pattern across southern Europe. Two important shifts in vegetation occur at 7700 cal yr BP (calendar years before present) and between 7500 and 7000 cal yr BP and are correlated with increased river inputs around the Adriatic Basin respectively from the northern (7700 event) and from the central Adriatic borderlands (7500-7000 event). During the mid-Holocene, the wet summers lead to permanent moisture all year resulting in a homogeneous seasonal precipitation regime. After 6000 cal yr BP, summer precipitation decreases towards present-day values while winter precipitation rises regularly showing the setting up of Mediterranean climate conditions. Multiproxy evidence from core MD 90-917 provides a deeper understanding of the role of precipitation and particularly the seasonality of precipitation in mediating vegetation change in the central Mediterranean during the Holocene

show abstract

“…Cacho et al, 2001;Asioli et al, 2001;Magny et al, 2006a;Fletcher et al, 2010). Data collected within the LAMA project clearly show how these cooling events in the central Mediterranean corresponded to wetter conditions marked by higher lake levels to the north of ca.…”

Section: Centennial-scale Eventsmentioning

confidence: 99%

North–south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses

et al. 2013

Self Cite

View full text Add to dashboard Cite

Abstract. On the basis of a multi-proxy approach and a strategy combining lacustrine and marine records along a north–south transect, data collected in the central Mediterranean within the framework of a collaborative project have led to reconstruction of high-resolution and well-dated palaeohydrological records and to assessment of their spatial and temporal coherency. Contrasting patterns of palaeohydrological changes have been evidenced in the central Mediterranean: south (north) of around 40° N of latitude, the middle part of the Holocene was characterised by lake-level maxima (minima), during an interval dated to ca. 10 300–4500 cal BP to the south and 9000–4500 cal BP to the north. Available data suggest that these contrasting palaeohydrological patterns operated throughout the Holocene, both on millennial and centennial scales. Regarding precipitation seasonality, maximum humidity in the central Mediterranean during the middle part of the Holocene was characterised by humid winters and dry summers north of ca. 40° N, and humid winters and summers south of ca. 40° N. This may explain an apparent conflict between palaeoclimatic records depending on the proxies used for reconstruction as well as the synchronous expansion of tree species taxa with contrasting climatic requirements. In addition, south of ca. 40° N, the first millennium of the Holocene was characterised by very dry climatic conditions not only in the eastern, but also in the central- and the western Mediterranean zones as reflected by low lake levels and delayed reforestation. These results suggest that, in addition to the influence of the Nile discharge reinforced by the African monsoon, the deposition of Sapropel 1 has been favoured (1) by an increase in winter precipitation in the northern Mediterranean borderlands, and (2) by an increase in winter and summer precipitation in the southern Mediterranean area. The climate reversal following the Holocene climate optimum appears to have been punctuated by two major climate changes around 7500 and 4500 cal BP. In the central Mediterranean, the Holocene palaeohydrological changes developed in response to a combination of orbital, ice-sheet and solar forcing factors. The maximum humidity interval in the south-central Mediterranean started ca. 10 300 cal BP, in correlation with the decline (1) of the possible blocking effects of the North Atlantic anticyclone linked to maximum insolation, and/or (2) of the influence of the remnant ice sheets and fresh water forcing in the North Atlantic Ocean. In the north-central Mediterranean, the lake-level minimum interval began only around 9000 cal BP when the Fennoscandian ice sheet disappeared and a prevailing positive NAO-(North Atlantic Oscillation) type circulation developed in the North Atlantic area. The major palaeohydrological oscillation around 4500–4000 cal BP may be a non-linear response to the gradual decrease in insolation, with additional key seasonal and interhemispheric changes. On a centennial scale, the successive climatic events which punctuated the entire Holocene in the central Mediterranean coincided with cooling events associated with deglacial outbursts in the North Atlantic area and decreases in solar activity during the interval 11 700–7000 cal BP, and to a possible combination of NAO-type circulation and solar forcing since ca. 7000 cal BP onwards. Thus, regarding the centennial-scale climatic oscillations, the Mediterranean Basin appears to have been strongly linked to the North Atlantic area and affected by solar activity over the entire Holocene. In addition to model experiments, a better understanding of forcing factors and past atmospheric circulation patterns behind the Holocene palaeohydrological changes in the Mediterranean area will require further investigation to establish additional high-resolution and well-dated records in selected locations around the Mediterranean Basin and in adjacent regions. Special attention should be paid to greater precision in the reconstruction, on millennial and centennial timescales, of changes in the latitudinal location of the limit between the northern and southern palaeohydrological Mediterranean sectors, depending on (1) the intensity and/or characteristics of climatic periods/oscillations (e.g. Holocene thermal maximum versus Neoglacial, as well as, for instance, the 8.2 ka event versus the 4 ka event or the Little Ice Age); and (2) on varying geographical conditions from the western to the eastern Mediterranean areas (longitudinal gradients). Finally, on the basis of projects using strategically located study sites, there is a need to explore possible influences of other general atmospheric circulation patterns than NAO, such as the East Atlantic–West Russian or North Sea–Caspian patterns, in explaining the apparent complexity of palaeoclimatic (palaeohydrological) Holocene records from the Mediterranean area.

show abstract

Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record

Cited by 159 publications

References 99 publications

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

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

Holocene vegetation and climate changes in the central Mediterranean inferred from a high-resolution marine pollen record (Adriatic Sea)

North–south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses

Contact Info

Product

Resources

About