Limited contribution by non‐volant small mammals to regeneration in ironstone rocky outcrops

Abstract Introduction Animal‐mediated seed dispersal contributes substantially to natural regeneration in degraded areas. However, the role of seed dispersal by non‐volant small mammals (NVSM), mainly marsupials and rodents, in contributing to regeneration remains underexplored, especially in mountaintop, open‐canopy ecosystems. Objectives The study assesses the role played by NVSM as seed dispersers in ironstone outcrop ( canga ) vegetation, strongly affected by iron mining. Methods We compared fruit removal by NVSM across vertebrate‐access and exclosure treatments during both rainy and dry seasons in both preserved and mining‐degraded canga in southeastern Brazil. We also retrieved seeds from feces of NVSM in both degraded and preserved canga and conducted germination experiments between control versus gut‐passed seeds. Results The fruit removal was higher in preserved canga areas, and in the rainy season. However, it was similar between vertebrate‐access and exclosure treatments. Only three out of 61 fecal samples retrieved from two species of NVSM ( Calomys tener and Monodelphis domestica ) contained seeds. The seeds in those feces belonged to a single plant species, Miconia oligochaeta (Melastomataceae). Germinability of gut‐passed seeds was null for C. tener and 3.6% for M. domestica , with control seeds germinating 11.2%. Conclusion Our results indicate that NVSM play limited roles as seed dispersers in canga ecosystems, suggesting a continuum between seed dispersal and seed predation by this group, reinforcing the idea that rock outcrop ecosystems are dispersal‐limited.