Pre-dispersal seed predation limits Ononis tridentata L. potential as a seed source for ecological restorations in semiarid gypsum soils

Ecological restoration strategies are designed to promote ecosystem recovery after human disturbance. Gypsum outcrops on the southeast of the Iberian Peninsula are highly biodiverse ecosystems recognized as a priority for the protection of Iberian Gypsum Vegetation (Gypsophyletalia). The Iberian gypsophyte Ononis tridentata subsp.tridentata is a crucial species for ecological restoration but pre-dispersal seed predation thwarts its suse. The aim of this research was to evaluate the potential of different locations with O. tridentata as seed sources. To achieve this, ten locations were compared based on habitat type (natural or restored) and distance to the mining lease (inside, adjacent, or distant). Fifteen unopened fruits were collected from ten plants in each location to assess total seeds, potentially viable seeds, and pre-dispersal seed predation per fruit. One-way analysis of variance was performed to compare locations, while the effects of habitat type and distance were evaluated using a linear mixed model for potentially viable seeds and a generalized linear mixed model with a gamma distribution for total seeds and pre-dispersal seed predation. Our results suggest that promising seed sources can be found in both natural and restored areas, regardless of the distance to the mining lease. However, the distance to mining lease affects pre-dispersal seed predation; higher values are found at greater distances. The low abundance of O. tridentata in restored locations may contribute to protection against predation. Furthermore, unique characteristics of the locations, plant density, seasonal variability, and genetic diversity are crucial factors that should be considered for select seed sources.