Examining the spatiotemporal variation of genetic diversity and genetic rarity in the natural plant recolonization of human-altered areas

Abstract

The spatiotemporal genetic variation at early plant life stages may substantially affect the natural recolonization of human-altered areas, which is crucial to understand plant and habitat conservation. In animal-dispersed plants, dispersers’ behavior may critically drive the distribution of genetic variation. Here, we examine how genetic rarity is spatially and temporally structured in seedlings of a keystone pioneer palm (Chamaerops humilis) and how the variation of genetic rarity could ultimately affect plant recruitment. We intensively monitored the seed rain mediated by two medium-sized carnivores during two consecutive seasons in a Mediterranean human-altered area. We genotyped 143 out of 309 detected seedlings using 12 microsatellite markers. We found that seedlings emerging from carnivore-dispersed seeds showed moderate to high levels of genetic diversity and no evidence of inbreeding. We found inflated kinship among seedlings that emerged from seeds within a single carnivore fecal sample, but a dilution of such FSGS at larger spatial scales (e.g. latrine). Seedlings showed a significant genetic sub-structure and the sibling relationships varied depending on the spatial scale. Rare genotypes arrived slightly later throughout the dispersal season and tended to be spatially isolated. However, genetic rarity was not a significant predictor by itself which indicates that, at least, its influence on seedling survival was smaller than other spatiotemporal factors. Our results suggest strong C. humilis resilience to genetic bottlenecks due to human disturbances. We highlight the study of plant-animal interactions from a genetic perspective since it provides crucial information for plant conservation and the recovery of genetic plant resilience.

Animal‐mediated seed dispersal and the demo‐genetic configuration across plant colonization gradients

“…While all frugivores disperse seeds from multiple source trees, their scats tend to hold seeds from nearby trees. This is an expected effect because a single scat is the product of a short foraging time lapse in which animals tend to visit neighbouring trees (García et al., 2009; Garrote et al., 2023), even more common for multi‐seeded species like J. phoenicea (Torimaru et al., 2007). However, at a deposition site scale, successive independent dispersal events (from both large and medium‐sized frugivores like V. vulpes or T. philomelos and small‐sized frugivores like E. rubecula ) culminate in a seed rain composed of progenies from multiple mother trees scattered throughout the landscape.…”