Seed-seed predator interactions of European beech, Fagus silvatica and forest rodents, Clethrionomys glareolus and Apodemus flavicollis

Oxford

1985

S. 149-156

4 Abb., 2 Tab., 28 Lit. Ang.

Bandaufführung

10480S

156263

Field and laboratory experiments on seed preferences of forest rodents in Denmark showed that among seeds from deciduous trees rodents preferred the large, energy- and nitrogen-rich seeds of Fagus, Quercus and Corylus. These seeds have not evolved morphological structures for wind dispersal, in contrast to other seeds tested. Radio-actively labelled seeds of Fagus silvatica L. were removed by rodents and cachet at 1-13 m (mean 4,13 m) distances from the point of falling. Seeds were scatter hoarded, the mean number of seeds per cache being 5.0. The typical burial site was a few ccn-timeters below the soil surface in the wall of a rodent runway. Burial of seeds led to higher germination as seeds deposited in the litter layer were killed by frost or drought. Predation of caches was high, however, in experiments more caches survived if a surplus of seeds were given or if rodent numbers were reduced. Age structure of saplings revealed that most individuals had germinated in years following "mast" years. Thus, there is a strong circumstantial evidence that rodents, by predation and dispersal of seeds, influece the population biology and evolution of Fagus silvatica. In turn, the synchronous production of seeds leadt to prolonged reproduction periods in the rodent species, resulting in outbreaks of voles.