Aldaketa klimatikoak kuaternarioan eta biogeografia historikoa: errefugio kantabrikoak

Abstract

[EUS] Azken Ziklo Glaziarrean eta Holozeno hasieran zehar emandako aldaketa klimatikoek Ipar Hemisferioko flora, fauna zein giza populazioaren okupazioan bariazio ugari eragin zituzten. GRAL honetan, landare komunitate ezberdinek aldaketa hauen aurrean izandako erantzuna aztertu da. Horretarako, Iberiar Penintsulako iparraldean Goi Pleistozenoan eta Behe Holozenoan erradiokarbono bitartez datatu diren aztarnategien sekuentzia antrakologikoak bildu dira datu-base batean, hauekin analisi kronologiko eta estatatistiko ezberdinak burutuz. Ikertutako datuek Azken Maximo Glaziarrean landare komunitate ezberdinek eskualde hau okupatu zutela adierazten dute, haien artean pinudiak, baso misto atlantikoa, artadi kantauriarra eta sastrakadi xero-heliofiloa esanguratsuenak izanik. Baldintza klimatiko gogorrenak eman ziren garaian, Azken Maximo Glaziarra bezala ezagutua, pinudiak eta sastrakadi xerofilo irekiak hedatuko dira, nahiz eta Betula edo Quercus robur bezalako taxoiak lokalki aurkitu kostaldeko eremuetan, hainbat elementu termo-Mediterraneorekin batera, hala nola Quercus ilex edota Arbutus unedo. Tardiglaziarrean zehar, eta Holozenoan bereziki, flora atlantikoa hedatu egingo da eskala erregional batean prezipitazioen eta tenperaturaren gorakadari erantzunez.

[EN] Changes in climatic conditions during the Last Glacial Cycle and the onset of the Holocene caused plenty of alterations in the Northern Hemisphere flora, fauna and patterns of human occupations. In this work, charcoal-based plant communities’ response to climate variability has been explored. For this purpose, anthracological sequences coming from Northern Iberian deposits dated back to Late Pleistocene and Early Holocene have been collected in a database and a series of chronological and statistical analysis have been made. The reviewed data shows that a variety of plant communities coexisted across the Last Glacial Period, comprising pinewoods, atlantic mixed forest, cantabrian holm-oak and xero-heliophilous shrubs. During the most harsh climate phase, namely the Last Glacial Maximum, pinewoods and open xeroheliophilous communities are spread in the region, although taxa such as Betula or Quercus robur were locally present in the coastal environments, together with thermoMediterranean elements such as Quercus ilex or Arbutus unedo. During the Lateglacial, and specially during the Holocene, Atlantic flora is spread regionally as a response to increased rainfall and temperatures.