Substrate scent-induced disproportionate seed dispersal by rodents

Conspecific adults impose strong negative density-dependent effects on seed survival nearby parent trees, however, the underlying mechanisms are diversified and remain unclear. In this study, we presented consistent evidence that parent-scented forest floor masked seed odor, reduced cache recovery rate by scatter-hoarding animals, and then increased seed dispersal far away from mother trees. Our results showed that seed odors of Korean pine Pinus koraiensis match well with the volatile profile of their forest floor. Moreover, scatter-hoarding animals selectively transported P. koraiensis seeds toward the areas where seed odor was more contrasting against the background substrate, possibly due to the fact that accumulation of conspecific volatile compounds in caches hindered seed detection by scatter-hoarding animals. Our study provides insight into the role of leaf litter in directing seed dispersal process, representing a novel mechanism by which P. koraiensis increases selection for seed dispersal far away from the parent tree.