We evaluated heavy metal deposition in Parmotrema arnoldii and Tillandsia usneoides in response to air pollution in Loja city, Ecuador. We assessed heavy metal (cadmium, copper, manganese, lead and zinc) content in these organisms at nine study sites inside Loja city and three control sites in nearby forests. Concentrations of all studied heavy metals (i.e., cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn) and zinc (Zn)) were highest in downtown Loja. Our study confirms that passive monitoring using lichens and/or bromeliads can be an efficient tool to evaluate heavy metal deposition related to urbanization (e.g., vehicle emissions). We recommend these organisms to be used in cost-effective monitoring of air pollution in tropical countries.

Los páramos presentan altos niveles de diversidad y endemismo de especies y son importantes en la regulación hidrológica. Sin embargo, es uno de los ecosistemas más amenazados debido a actividades agrícolas y ganaderas. Los briófitos son un importante componente en términos de diversidad, bio-masa y funcionamiento de estos ecosistemas. Estos organismos poiquilohídricos son muy sensibles a cambios en el microclima relacionados con la humedad, luz y temperatura. Se evaluaron los efectos de las variables climáticas y topográficas sobre la diversidad de briófitos terrícolas en tres cimas del páramo del Parque Nacional Podocarpus, Ecuador. En cada cima se establecieron ocho parcelas de 1 × 1 m, donde se registró la incidencia y cobertura de briófitos terrestres. Se establecieron diferencias en la composición de especies de las tres cimas mediante un análisis de escalamiento multidimensional no métrico (EMNM) y los efectos de las variables climáticas y topográficas mediante un análisis multivariante basado en permutaciones (PERMANOVA). Nosotros encontramos que las diferencias en las comunidades de briófitos terrícolas estuvieron correlacionadas con la precipitación y pendiente. Se evidenció que las cimas con mayores niveles de precipitación y menos pendiente fueron importantes para la distribución y establecimiento de las comunidades de briófitos relacionados con una mayor retención de humedad del suelo.

Neotropical montane forests are considered biodiversity hotspots, where epiphytic bryophytes are an important component of the diversity, biomass and functioning of these ecosystems. We evaluated the richness and composition of bryophytes in secondary successional forests and mixed plantations of Juglans neotropica. In each forest type, the presence and cover of epiphytic bryophytes was registered in 400 quadrats of 20 cm × 30 cm. We analyzed the effects of canopy openness, diameter at breast height (DBH) and forest type on bryophyte richness, using a generalized linear model (GLM), as well as the changes in species composition using multivariate analysis. Fifty-five bryophyte species were recorded, of which 42 species were in secondary forests and 40 were in mixed plantations. Bryophyte richness did not change at forest level; however, at tree level, richness was higher in the mixed plantation of J. neotropica compared to the secondary forests, due to the presence of species adapted to high light conditions. On the other hand, bryophyte communities were negatively affected by the more open canopy in the mixed plantation of J. neotropica, species adapted to more humid conditions being less abundant. We conclude that species with narrow microclimatic niches are threatened by deforestation, and J. neotropica plantations do not act as refuge for drought-sensitive forest species present in secondary forests.