Multiscale variability in nutrients and secondary metabolites in a bat‐dispersed neotropical fruit

Abstract

Ripe fleshy fruits contain not only nutrients but also a diverse array of secondary metabolites. Nutrients serve as a reward for mutualists, whereas defensive metabolites protect the fruit against pests and predators. The composition of these chemical traits is highly variable, both across different plants and even within repeating structures on the same individual plant. This intraspecific and intraindividual variation has important fitness consequences for both plants and animals, yet patterns of variation and covariation in nutrients and secondary metabolites are not well understood, especially at smaller scales. Here, we investigate the multiscale variation and covariation between nutrients and defensive metabolites in Piper sancti‐felicis ripe fruits. Means and measures of variation of sugars, proteins, phenolics, and alkenylphenols vary greatly among plants, and at least 50% of the trait variation occurs at the intraindividual level. Also, we found that proteins, but not sugars, were correlated with phenolics and alkenylphenols at multiple scales, suggesting trait variation in protein content may be more constrained than sugars. Our findings emphasize the importance of examining patterns across scales and provide the groundwork to better understand how complex patterns of variation and covariation in nutrients and defensive metabolites shape ecological interactions surrounding fruits.

Importance of plant and fruit traits on the structure of bird seed dispersal networks in different disturbed habitats

“…Therefore, variations in fruit nutrient traits that influence frugivore decisions to optimize energy intake can have implications for the structure of seed dispersal networks (Schupp 1993; Jordano & Schupp 2000). Furthermore, fruits often contain complex mixtures of toxic or deterrent secondary metabolites, which can negatively impact seed dispersal mutualisms by reducing the quantity or quality of interactions between frugivores and plants (Gelambi & Whitehead 2023; Nelson et al. 2023).…”

“…We also analyzed the fruit nutrients and secondary metabolites, including amylase, crude fat, wet weight, dry weight, crude protein, total sugar, tannin, total phenols, alkaloids, and dry matter (Crestani et al. 2019; Gelambi & Whitehead 2023).…”

“…2018). Moreover, fruits often contain complex mixtures of toxic or deterrent secondary metabolites that can reduce the quantity or quality of seed dispersal mutualisms (Gelambi & Whitehead 2023; Nelson et al. 2023).…”

Interactions between nutrients and fruit secondary metabolites shape bat foraging behavior and protein absorption

“…Among these, the "nutrient-toxin titration hypothesis" predicts that frugivores will select high-nutritional fruits, regardless of the concentration of defensive traits, as nutrients can offset potential adverse effects from toxin consumption. The interactive effect between nutrients and secondary metabolites has been investigated by evaluating frugivore removal rates in natural and artificial conditions (Cazetta et al, 2008;Cipollini & Levey, 1997b;Schaefer et al, 2003) and by assessing the correlation between nutrients and various groups of defensive metabolites within fruit pulp (Gelambi & Whitehead, 2023;Izhaki et al, 2002). Some of these studies align with the predictions of the nutrient-toxin titration hypothesis, but its applicability seems to depend on the system and the type of secondary metabolites studied.…”