Projected Impacts of Climate Change on Interactions Between Plants and Avian Frugivores Across the Americas

Abstract

Aim

Frugivorous birds provide crucial seed-dispersal functions in terrestrial ecosystems. However, the impact of climate change on plant–avian frugivore interactions remains unclear due to past methodological limitations. In this study, we address this by mapping these interactions across the Americas and projecting shifts in interaction diversity under future climate scenarios.

Location

North, South, and Central America.

Time Period

Present (1980–2010) and future (2070–2100).

Major Taxa Studied

Frugivorous birds and fleshy-fruited plants.

Methods

Using a trait-matching framework, we estimated interaction probabilities between frugivorous birds (n = 539 species) and fleshy-fruited plants (n = 3280 species) at the ecoregion level. To estimate climate impacts, we modeled how interaction probabilities will change under future scenarios based on the overlap between avian climate niches and ecoregion climates. From these probabilities, we calculated plant–frugivore interaction diversity as the effective number of avian partners for a given plant species in an ecoregion. We then used simulations to examine how avian dietary flexibility and dispersal may buffer future diversity of plant–frugivore interactions.

Results

Under future climate scenarios, our models projected a decline in interaction diversity across most ecoregions, especially in tropical and subtropical biomes. Simulations indicated that interaction rewiring through dietary flexibility and dispersal could partially mitigate losses of interaction diversity, particularly in tropical forests.

Main Conclusions

Our results suggest that the diversity of plant–frugivore interactions in the Americas will decline in response to climate change, potentially undermining the stability of seed-dispersal functions. We also show that the resilience of this function depends on the capacity of frugivorous birds to modify their geographic ranges or dietary preferences. However, the extent to which avian dispersal and adaptation will regulate future species interactions remains unknown, highlighting the importance of maintaining high plant–frugivore interaction diversity in current assemblages to buffer ecosystems against future climatic changes, especially in the tropics.