Early to Middle Pleistocene dynamics of plant and mammal communities in South West Europe

Abstract

For the first time, the general trends of large mammal fauna changes in SW Europe during the Middle Pleistocene Revolution (MPR) have been compared with the coeval vegetation dynamics. Both vegetation and animal communities significantly varied during the MPR, but with different regional timings and modes. A number of new and last appearances are found in mammals, so that there is no substantial loss of richness. By contrast, since at least 1.5Ma no new tree genera are recorded in SW Europe, while many taxa progressively disappeared and their range was occupied by taxa already present in the region. Compared to animals, plant communities show a remarkable persistence, so that in many cases many modern tree populations may be direct descendants of the Early Pleistocene ones in the same region. No such case of long-term persistence since at least the late Early Pleistocene is observed in the faunal record, which underwent a complex history of species turnovers, mainly related to dispersal events, and competitive exclusions, but also originations of endemic species. A comparison among regional trends in SW Europe shows a marked increase in regionalization during the MPR in the faunal record, while only modest differences are found in the vegetation dynamics of N Spain, S France and central Italy. On the whole, disentangling the relationships between vegetation and mammals at time scales of 105 years is a very complex task, due to different patterns of change in relation to climate oscillations.