Mammal diversity during the Pleistocene-Holocene transition in Eastern Europe.

Abstract

Fossil record data on the mammal diversity and species richness are of importance for the reconstruction of the evolution of terrestrial ecosystems during the Late Pleistocene-Holocene transition. In Eastern Europe, the transformations during the Pleistocene-Holocene transition consisted mainly in changes in zonal structure and local fauna composition (Markova & Kolfschoten 2008). We investigated the species richness and the analogues of the α, β diversity indexes (in the sense of Whittaker 1972) of large and medium size mammals for 13 climate-stratigraphic units dating to the Late Pleistocene and the Holocene, from the Hasselo Stadial (44-39 kBP) to the Subatlantic period and the present day. The biological diversity of the Last Glacial Maximum (LGM) and the Holocene thermal optimum was investigated in more detail using information about all mammalian taxa (PALEOFAUNA database; Markova 1995). One of our results show that the α, β diversity values show only a negative correlation with the temperature conditions during the Late Pleistocene, the period that is characterized by the so-called 'Mammoth Fauna' complex. For the Holocene faunas the diversity indexes are nearly independent from physical conditions; the α diversity index decreased and the β diversity index increased. The relatively low α diversity and high β diversity indexes for the present-day faunas are referred to the decrease of the population number of some forest species in historical time and the increase of the dominance of unspecialized species or the species connected with intra-zonal ecosystems. The study shows furthermore the occurrence of several East European 'centers' with a high mammal diversity, which are relatively stable during the Pleistocene-Holocene transition. The orientation of the boundaries between the large geographical mammal assemblages depended, particularly in the northwestern part of Eastern Europe, on the expansion of the Scandinavian ice sheet.