Glacial refugia of temperate, Mediterranean and Ibero‐North African flora in south‐eastern Spain: new evidence from cave pollen at two Neanderthal man sites

Abstract

Aim To locate glacial refugia of thermophilous plant species in Spain. Location Two south‐eastern Spanish Neanderthal man sites in Murcia; namely, the inland Cueva Negra del Estrecho del Río Quípar and the coastal Sima de las Palomas del Cabezo Gordo. Methods We use pollen found in cave sediments as a source of palaeobotanical and palaeoecological information. The findings are discussed with regard both to animal remains from both sites, and also to other refugia in south‐eastern Spain and elsewhere in the Iberian Peninsula. Results Both sequences show persistence of abundant mesothermophilous trees during the last glacial stage, suggesting both localities were reservoirs of phytodiversity and woodland species. At both sites, deciduous and evergreen oaks are the most abundant components, followed by a wide variety of deciduous trees and sclerophyllous shrubs, including Ibero‐North African xerothermic scrub near the coast. Conclusions Incomplete information underlies a common misapprehension that Iberian glacial refugia were confined to southernmost parts of the peninsula. A rather different picture of Quaternary refugia emerges from consideration of pollen sequences from caves (and other inputs such as macroscopic charcoal, spatial genetic structure of present‐day populations, faunal remains, and present‐day distribution of thermophilous species). This picture offers a view of numerous viable areas for woodland species in southern Spain, in addition to others in the mountain ranges, both in continental central Spain and those of northern Spain: these stretch from the Mediterranean coast of Catalonia to the westernmost extent of the Bay of Biscay.

Neanderthal diets in central and southeastern Mediterranean Iberia

“…The region has long been the focus of palaeoenvironmental research, particularly because it was a refugium during several different glacial periods for temperate and Mediterranean flora and fauna (Hewitt, 1999;Barroso et al, 2006c;Gómez and Lunt, 2007). Even today, southeastern Iberia is considered a biodiversity hotspot (Mota et al, 2002;Carrión et al, 2003). Though these clement ecosystems were considerably more widespread across Europe during interglacial periods (Wenzel, 2007), the diversity and longevity of temperate forest ecosystems late into the Middle Pleistocene in southeastern Iberia distinguishes the ecological potential of this European subregion.…”

“…Pines, evergreen oaks and deciduous oaks are widespread (Carrión et al, 2003). Open grasslands are implied by Poaceae and Chenopodiaceae, with stands of pines (Pinus nigra and Pinus sylvestris) co-existing and in constant progression or regression with an evergreen-forested fringe area of oak (Quercus sp.…”

“…celtiberica). Nearby coastal saltpans and marshes are indicated by Chenopodiaceae, boxthorn (Lycium) and paternostrera (Withania frutescens), while thermophytes such as dogbane (Periploca angustifolia) or red spike thorn (Maytenus europaeus) that readily succumb to frost imply that the mean annual temperature at Sima de las Palomas was much like today, perhaps barely 2 C lower (Carrión et al, 2003;Jennings et al, 2011). It is nevertheless likely that elsewhere mean annual temperatures might well have fallen to 10 C below present values, particularly on high ground away from the coast or in more northerly latitudes around the central Mediterranean region of Iberia (Badal et al, 2012).…”

Holocene fire activity and vegetation response in South-Eastern Iberia

“…Broadly speaking a tendency towards warmer and wetter climate is found in all the records considered in the present analysis where broadleaved trees -both evergreen and deciduous -replaced conifers in most sites. Some of these areas would have acted as glacial refugia, enclosing some marginal oak forests that would have remained over the glacial and postglacial period (Brewer et al, 2002;Carrión et al, 2003b;Petit et al, 2002). Broadleaved elements were continuously present at the coastal mountain areas since the beginning of the Holocene, while in the intramontane regions and the lowlands the spreading of deciduous forest began abruptly at ca.…”

Bayesian age-depth modelling of Late Quaternary deposits from Wet and Blanche Caves, Naracoorte, South Australia: A framework for comparative faunal analyses

“…Caves also provide stable conditions for the long term preservation of skeletal remains of a diverse range of vertebrates, which may have been collected through pitfall entrapment, cave inhabitant death and/or carnivore accumulation (Nielsen-Marsh, 2000). In some cases, vertebrate deposits in caves are associated with a range of other palaeoecological materials such as charcoal, calcium carbonate cave formations (speleothems) and pollen, which may be correlated with fossil faunal assemblages to provide a more accurate interpretation of past environmental conditions (e.g., Burney et al, 2001;Carrión et al, 2003;Auler et al, 2006). The application of Bayesian age-depth models to cave sequences has been valuable where the complex and sometimes random nature of accumulation processes in caves can limit the resolution and accuracy of chronologies for these sites (e.g., Jacobi and Higham, 2009;Blockey and Pinhasi, 2011;Pinhasi et al, 2011).…”