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

Jorge Isla Escudero, Miguel Jacome-Flores, Cristina Rigueiro, Juan Miguel Arroyo, Pedro Jordano, Cristina Garcia Perez

Research output: Contribution to journalArticlepeer-review

Abstract

1.Ecologists have long recognized that seed dispersal mutualisms trigger natural regeneration and range expansion of animal-dispersed trees. Yet we lack empirical studies addressing whether frugivore activity counteracts influences founder effects, which reduce genetic diversity at the colonization front of expanding populations.

2.Here we evaluate the contribution, from both demographic and genetic perspectives, of animal frugivores dispersing seeds across an expansion gradient. We used DNA barcoding for frugivores identification and highly polymorphic genetic markers (SSRs) for maternal analysis of juniper seeds to investigate how (1) stand maturity, (2) microhabitat types, and (3) foraging patterns shape the distribution of the maternal progenies along this gradient.

3.We expect a reduced seed rain density and low numbers of source trees contributing to the seed rain at the colonization front, with limited availability of local fruiting trees. We also anticipated that larger frugivore species would promote maternally rich seed rain due to their capability to mix progenies in their stomachs and move further distances across the landscape.

4.Contrary to our expectations, we found that all identified frugivores produced dense and genetically diverse seed rains across the expansion gradient, even at the colonization front characterized by the scarcity of local fruiting trees.Contrary to our expectations, we found that frugivores generated dense, genetically diverse seed rains across the entire expansion gradient, even at the colonization front with a scarcity of local fruiting trees.

5.Our findings shed light on the fundamental and applied implications of plant-frugivore interactions in shaping highly diverse second-growth forests. These results emphasize the necessity of preserving plant-animal mutualistic interactions to ensure the persistence and expansion of natural tree populations, particularly in formerly fragmented landscapes.
Original languageEnglish
JournalJournal of Ecology
VolumeIn Press
Publication statusAccepted/In press - 26 Jan 2024

Keywords

  • Plant population and community dynamics
  • second-growth
  • expanding forest
  • seed dispersal
  • plant-animal mutualisms
  • maternal progenies
  • microhabitat
  • stand maturity
  • frugivore's foraging patterns
  • natural regeneration
  • Mediterranean forests

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