Seed fate in a population of Carex pilulifera L. : II. Seed predation and its consequences for dispersal and seed bank.

Seed predation of the myrmecochorous Carex pilulifera (Cyperaceae) was studied in a wood land area in NE Zealand, Denmark. Experiments demonstrated that predation by mice, Sylvaemus flavicollis, and ground beetles, Harpalus fuliginosus, reduced the seed pool of a C. pilulifera population by approx. 21% and 65%, respectively. The use of exclosure experiments in studies of predation is discussed and criticized. Evidence indicated only a small degree of competitive interaction between the two predator species and between predators and seed-dispersing ants. The possible evolutionary consequences of predation for seed set, dispersal, and phenology are discussed. Although the study indicated that the number of seeds surviving in soil decreased exponentially with time, the presence of a persistent seed bank in C. pilulifera was demonstrated.