29 juillet 2024
Pauly et al., « Endozoochorous seed dispersal by brown bear (Ursus arctos) in the Pyrénées: angiosperms but also ferns and mosses and the importance of disaggregation agents », Recherche Data Gouv, ID : 10.57745/CPS1V3
Premise: Endozoochory by megafauna enables temperate mountain plants to disperse over long distance. As an endozoochorous agent, brown bear may play a unique role through its biology and ecology especially because of its very diverse diet (angiosperms, ferns, mosses). However, few studies have been conducted on the dispersal of all angiosperms and none on ferns or mosses. Also, the fact that the faecal matrix could represent a barrier for the germination of dispersed seeds due to various constraints, has often been neglected. Methods: In this study, we investigated endozoochory by the European brown bear and the effect of the faecal matrix on the germination success. We conducted a seedling emergence monitoring experiment in greenhouse during seven months to assess seed dispersal potential based on 86 faeces. Each sample was split into two modalities (raw vs. filtered faeces), to test the effect of the faecal matrix on seedling germination and growth. Key results: We found that brown bear dispersed not only fleshy-fruited plants, but also dry-fruited plants, and for the first time among Ursids, ferns and mosses. We also pointed out that the faecal matrix acts as an important barrier for germination with little effect on growth. Conclusions: These results highlight the role of Brown Bear in the dispersal of non-fleshy-fruited plants, and suggest that the spectrum of plant species dispersed by Brown Bear is wider than formerly thought. They also stress the importance of faeces disaggregation on seed dispersal outcomes, a mechanism mediated by abiotic or biotic agents.