Table 1.
Network centrality indices used to identify possible keystone plant species and average values and variance of each index.
Table 2.
List of plant species included in analyses, showing the sample size (hours of observations), the total number of frugivores known to consume the fruits, the proportion of fruits handled by primates, seed predatory birds (e.g. Psittacidae) and other birds, and the coefficient of determination (R2) indicating the proportion of the variation explained by the abundance of frugivores.
Fig 1.
Frugivore-plant network for the species studied in Tinigua National Park, Colombia.
The most connected frugivores were woolly monkeys (Lagothrix lagothricha), spider monkeys (Ateles belzebuth), brown capuchins (Cebus or Sapajus apella), white-throated toucan (Ramphastus tucanus), ivory-billed toucan (Pteroglossus flavirostris), common piping-guan (Pipile pipile) and howler monkeys (Alouatta seniculus). The complete list of plant species appears in Table 1; animal species names are provided in the Supplementary Material (Tables C and SD).
Fig 2.
Principal components analysis based on the number of fruits consumed by different frugivore species of 73 canopy plants in an upper Amazonian forest.
Table 3.
Association between nutrient content in fruit pulp (% lipids) and other plant-frugivore traits.
The table shows the expected relationships according to the generalized vs. specialized hypothesis, and the coefficients of determination.
Fig 3.
NMDS ordination of plant species based on plant traits that have been used to define specialized vs. generalized dispersal systems.
The relevance of each trait is also indicated, for instance, showing that the x-axis is positively associated with visitation rate and that the y-axis is negatively associated with the concentration of lipids in fruit pulp.
Fig 4.
Frequency of species showing aggregated, random and dispersed patterns of phylogenetic aggregation according to NRI and NTI indices.
Black bars represent species that differ from random (i.e. are more aggregated or dispersed than expected by chance, gray bars).
Table 4.
Most important plant species for the frugivore community in Tinigua National Park, according to two approaches.
Left side: Pulp biomass going to the frugivore level (taking into account plant density of reproductive trees, crop size, pulp in the fruit, and the amount of fruits consumed). Right side. Plant species producing significant amounts of fruits in periods of scarcity for a variety of consumers (see details in [43]). The plant species in common in both lists are highlighted in bold.
Fig 5.
NMDS ordination of plant species consumed by frugivores, based on the indices describing the structure of frugivore-plant network.
Blue represents core species while green represents periphery species based on the classification used by [69].
Table 5.
Comparison of methods to estimate keystone plants from the amount of pulp biomass (Pulp) going to the frugivore level and different indices using topological networks (described in Table 1), based on correlations.
High correlations (r > 0.6) are highlighted.