Work

Squirrel nut-storage behavior contributes to a seedling spatial pattern resembling conspecific negative density dependence in a tropical forest

Year: 2026

Type: article

Abstract: : Conspecific negative density dependence (CNDD) is widely regarded as a key mechanism maintaining plant diversity and is classically attributed to host-specific pathogens or herbivores. However, whether animal-mediated seed dispersal may contribute to CNDD-like spatial patterns remains poorly understood. Such animal-mediated seed dispersal behaviors are widespread in forests but are difficult to study because of their stochastic nature. Here, we investigated the distance-dependent spatial distribution of seedlings of two Cyclobalanopsis species around parent trees (at seven distances from 0 to 30 m) in a tropical forest, comparing directions with and without observed nut-storage activity by two squirrel species that actively carve and store nuts away from parent trees. Results showed that seedling numbers exhibited a clear nonlinear distance-dependent pattern along directions with squirrel nut-storage activity, with significantly higher numbers at 20 m than in both same-tree and different-tree controls. Pathogen infection in sapling fine roots did not show a significant distance-dependent pattern. These findings provide a new perspective on CNDD-like pattern formation by highlighting animal-mediated seed redistribution as an additional process that may be associated with seedling spatial patterns.

Source: Forest Ecosystems

DOI: 10.1016/j.fecs.2026.100527