Late Pleistocene-Holocene spanish small mammal assemblages

Small mammals are considered good palaeoecological proxies for assessing climate and environmental fluctuations through time. The work here presented proposes a revision of the environmental dynamics of the Iberian Peninsula through the study of small mammal communities over the last 20,000 years, considering climatic evolution, taphonomic aspects and anthropogenic influences. Results obtained reveal a strong regionalization pattern across five ecogeographic regions. During the late Pleistocene, small mammal communities were characterized by species with central-European affinity, particularly in the North, North-East, and Central-North regions, reflecting higher abundances in open humid and rocky areas. By contrast, the Central-South and East regions do not reflect important variations in comparison with the Holocene epoch, which reported important changes in landscape composition and small mammal communities. These results are the consequence of the establishment of Mediterranean conditions in all the ecogeographic regions analysed since the Mid Holocene onwards, showing an increase in open environments across all regions. Evidence of anthropogenic impact on the small mammal communities has also been observed for several of the sites analysed, being especially notable during the Late Holocene, due to the introduction of synanthropic species. Taphonomic analyses have been neglected at some sites and our results highlight the importance of such studies for accurate palaeoenvironmental inferences, as biases in prey size/taxonomic composition were observed at some sites. Furthermore, although Holocene climate pulses are usually difficult to detect, the 4.2 ka Bond Event was recognized on the basis of small mammal assemblages. These climatic fluctuations were detected in certain locations in the northern areas of the Peninsula, reinforcing the presence of a strong regionalized response of the small mammal communities and environments to climate change in the Iberian Peninsula.