FRUIT ECOLOGY OF EOCENE AND NEOGENE PLANT ASSEMBLAGES IN EUROPE: TRACING SHIFTS IN DISPERSAL SYNDROMES

Abstract

We analyze 35 Eocene and Neogene floras from Europe (fruits, leaves, and pollen of woody taxa) to trace fruit dispersal syndromes in the fossil record. These derive from vegetation units spanning paratropical broad-leaved evergreen, mixed mesophytic, broad-leaved evergreen, and broad-leaved deciduous forests. The dispersal syndromes distinguished are fleshy and nonfleshy zoochorous, anemochorous, autochorous, and hydrochorous. Additionally, zonal and azonal taxa were distinguished to test whether the dispersal syndromes are equally distributed reflected in the zonal and azonal record. The results show very similar proportions of dispersal modes in the fossil record compared to modern forests. This suggests a consistent relationship in the Northern Hemisphere between vegetation type and dispersal spectrum in the last 50 million years. Paratropical forests show the highest values of fleshy zoochorous taxa and the lowest of anemochorous taxa. Fleshy zoochorous proportions remain high in broad-leaved evergreen forests. They are lower in subhumid sclerophyllous and lowest in broad-leaved deciduous forests. For anemochorous taxa this trend is inverted: lowest values derive from paratropical forests and highest from subhumid sclerophyllous and broad-leaved deciduous forests. Nonfleshy zoochorous taxa always show relatively low percentages but their values are somewhat higher in subhumid sclerophyllous and broad-leaved deciduous forests than in broad-leaved evergreen forests. Autochorous and hydrochorous dispersal modes are always very low. Whether in the Eocene or Neogene, the azonal record always has a higher anemochorous fraction. Because climate change instigates vegetational change, our findings link climate to changing resources for smaller vertebrates, although the consistent availability of nonfleshy zoochorous fruits since the late Eocene suggests a consistent resource, especially for rodents.