Alejandro R. Villa

Interactions between plants and hummingbirds form a key mutualistic pollination system underlying much of Neotropical biodiversity, and understanding their structure and variability is essential for predicting ecosystem responses to climate change and habitat loss. However, most evidence comes from local interaction networks, generating major knowledge gaps in both species’ geographic coverage (Wallacean shortfall) and documented biotic interactions (Eltonian shortfall). We conducted a continental-scale synthesis of published plant–hummingbird interaction networks across the Americas to evaluate how well current data represent geographic, environmental, taxonomic, and trait dimensions of the Trochilidae and their plant partners. The compiled dataset includes 12,658 recorded interactions involving 214 hummingbird species (~60% of the family) and 1,757 plant species. Network records are strongly concentrated in a few countries and predominantly in warm, humid, tree-covered environments, leaving large geographic regions and seasonal climates underrepresented. Taxonomic coverage is uneven, with Emerald and Hermit clades relatively well represented in published networks, while approximately 40% of all hummingbird species remain entirely unrecorded. Representation of threatened species is particularly limited, with very few Endangered or Critically Endangered species recorded. Cross-network centrality analyses show that a small subset of hummingbird and plant species repeatedly occupy central interactive roles, but these patterns are closely aligned with sampling intensity rather than geographic range size, indicating potential bias in inferred functional importance. By integrating network structure, species traits, and environmental characterization, this study provides a macroecological assessment of current knowledge on plant–hummingbird interactions. Our results identify priority gaps in species and regional coverage and highlight the need for targeted sampling to improve ecological inference and conservation planning for hummingbird pollination systems across the Americas.

The conservation status of the Colombian Caribbean dune system was assessed considering the influence of natural and anthropogenic factors. The study took place in five locations with a gradient of human disturbance. In total, 198 plots and 22 transects were established, three transects in Gairaca and Costa Verde; four in Lipe, and six in Mendihuaca and Salguero. Environmental variables such as dune height, slope, sediment physical–chemical attributes, and anthropogenic impact were assessed in each site, while species composition, frequency, and plant cover were determined for each plot. The results show a correlation between natural and anthropogenic factors and the composition and structure of plant communities growing on the beach and coastal dunes. Human disturbances (urbanized areas, construction, burning, debris, trampling, logging, tourism, groins, sewage, roads, garbage, and sediment extraction) were particularly relevant. Plant cover and species diversity were inversely related to human impact and disturbance. Furthermore, community structure varied among sites: trees and vines were more frequent in the preserved locations, while shrubs and parasitic plants were more abundant in the disturbed sites. Management alternatives should consider the environmental factors (natural and anthropogenic) affecting vegetation to improve the conservation of plant diversity on coastal dunes along the Colombian Caribbean coast.

Antecedentes y Objetivos: La supervivencia de epífilos como líquenes, hepáticas y algas en regiones tropicales húmedas está fuertemente influenciada por factores abióticos como la humedad y temperatura ambiental. Sin embargo, factores bióticos como las características morfológicas del hospedero o la competencia con otros epífilos rara vez son considerados. El objetivo de este estudio fue analizar el efecto del microclima y de la especie de forófito en la predominancia de líquenes foliícolas, hepáticas foliosas y algas.Métodos: La predominancia de epífilos se evaluó en dos sitios del sotobosque de la reserva Estación de Biología Tropical de Los Tuxtlas, cada uno con diferentes condiciones microclimáticas (alta humedad con baja temperatura y baja humedad con alta temperatura) y en dos especies de forófitos (Astrocaryum mexicanum y Danaea nodosa). A través de muestreo dirigido, se colectaron tres foliolos de seis individuos de cada especie en ambos sitios. Se calculó la predominancia de epífilos en 36 foliolos de cada especie, usando tres transectos aleatorios de 30 × 1 mm en cada foliolo. Se contó la presencia de hepáticas foliosas, líquenes foliícolas y algas verdes en cada 1 mm2, equivalente a una unidad de muestreo. Para determinar si el micrositio y la especie de forófito influyen en la predominancia de los epífilos, se realizaron pruebas de contraste de media entre cada grupo de epífilo: hepáticas, líquenes, algas y las asociaciones entre ellos. Resultados clave: El tipo de hospedero influyó más en la predominancia de líquenes que las condiciones microclimáticas. En cambio, ambos factores fueron significativos para hepáticas y algas.Conclusiones: Los resultados indican que la predominancia de epífilos en las hojas es un proceso en el que intervienen no sólo las variaciones microclimáticas; también influyen las características inherentes de las plantas hospederas.

The conservation status of the Colombian Caribbean dune system was assessed considering the influence of natural and anthropogenic factors. The study took place in five locations with a gradient of human disturbance. In each site, twenty-seven plots were established along three transects perpendicular to the coast. Environmental variables such as dune height, slope, sediment physical-chemical attributes, and anthropogenic impact were assessed in each site, while species composition, frequency, and plant cover were determined for each plot. The results show a correlation between natural and anthropogenic factors and the composition and structure of plant communities growing on the beach and coastal dunes. Human disturbances (urbanized areas, construction, burning, debris, trampling, logging, tourism, groins, sewage, roads, garbage, and sediment extraction) were particularly relevant. Plant cover and species diversity were highest in the sites with the lowest human impact, while the contrary occurred in sites where human impact was highest. Furthermore, community structure varied among sites: trees and vines were more frequent in the preserved locations, while shrubs and parasitic plants were more abundant in the disturbed sites. Management alternatives should consider the environmental factors (natural and anthropogenic) affecting vegetation to improve the conservation of plant diversity on coastal dunes along the Colombian Caribbean coast.