Secondary dispersal of jeffrey pine seeds by rodent scatter-hoarders: the roles of pilfering, recaching and a variable environment

摘要

It is increasingly apparent that dispersal of seeds from a plant to safe establishment sites is often a complicated, multistage process (Westoby, 1981; Forget and Milleron, 1991; Levey and Byrne, 1993; Chambers and MacMahon, 1994; Bohning-Gaese et al., 1999; Hoshizaki et al., 1999). At each stage, the vehicle or mode of dispersal can change. The initial stage of dispersal, movement from the parent plant to a substrate, is usually referred to as primary dispersal; all subsequent movements of the seedare termed secondary dispersal. The steps that a seed takes during dispersal and the ways it is treated have important influences on its ultimate fate. Consequently, a detailed knowledge of seed movements is necessary if we are to bridge the gap betweenstudies of seed dispersal and plant demography.