Defaunation Increases Clustering and Fine-Scale Spatial Genetic Structure in a Small-Seeded Palm Despite Remaining...

Area of Science:

• Ecology
• Conservation Biology
• Genetics

Background:

• Anthropogenic pressures like hunting cause wildlife loss (defaunation) in tropical forests, impacting species interactions and ecosystem services.
• While defaunation's effects on large-seeded plants are known, its impact on small-to-medium-seeded plants, dispersed by various frugivores, remains unclear.
• Small-seeded plants may be vulnerable to defaunation despite having diverse dispersers.

Purpose of the Study:

• To investigate the spatial and genetic consequences of defaunation on the medium-to-small-seeded palm Euterpe precatoria.
• To assess how varying levels of defaunation influence plant community structure and genetic patterns.

Main Methods:

• Studied Euterpe precatoria across three tropical forest sites with differing defaunation levels.
• Analyzed spatial genetic structure, seedling clustering, and nearest-neighbor distances.
• Assessed inbreeding and genetic diversity within plant populations.

Main Results:

• Defaunation correlated with increased fine-scale spatial genetic structure among Euterpe precatoria seedlings.
• Seedling cohorts and seedlings relative to adults showed increased spatial clustering.
• Nearest-neighbor distances between seedlings and adults decreased in defaunated areas.
• No significant effects on inbreeding or overall genetic diversity were detected.

Conclusions:

• Defaunation may reduce seed dispersal effectiveness even for small-seeded plants previously thought resilient.
• Observed clustering and reduced distances suggest impaired long-distance seed dispersal.
• Potential for negative downstream effects on genetic diversity warrants further investigation.