Format: ORAL

Vctor Gonzlez-Garca1, Eduardo Fernndez-Pascual1, Borja Jimnez-Alfaro1

1Biodiversity Research Institute-IMIB (CSIC-Univ. Oviedo-Princ. Asturias), Mieres, Spain

Southern European peninsulas provided refugia for temperate and mediterranean ecosystems during the Last Glacial Maximum (LGM). Despite pollen data, fossils and distribution modelling have been all used to understand vegetation during the LGM, we still lack a spatially explicit approach to map ecosystem types from modern climatic analogues. Here, we develop a framework for mapping ecosystem diversity of North-Western Iberian Peninsula during the LGM. First, we classified the Iberian Peninsula in climatic regions based on LGM climatic models and k-means unsupervised classification. The selected regions were sampled to conduct distribution models that were extrapolated to modern climates of Europe to detect modern climatic analogues. The areas with the highest climatic similarity to each one of the Iberian LGM regions were characterized with recent vegetation data to estimate the relative dominance of functional ecosystem types under modern climate conditions. In addition, we performed distribution models for modern forest types occurring in the ecoregion as a second approach to understand changes in the forest distribution. Our results highlight the complexity of Iberian ecosystems during the LGM, including mixed distribution of temperate and mediterranean climates as detected by modern analogues. We also found a similar bioclimatic zonation of the Iberian Peninsula in both LGM and modern climates, with the northwestern regions experiencing a relative stronger Atlantic influence. Additionally, available pollinic records were used to validate the potential vegetation of the Iberian Peninsula during LGM. Our approach allowed us to establish new hypotheses about the LGM distribution of ecosystem types in southern Europe, to be used in historical and ecological biogeography.