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.
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.
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.
Epiphytic bryophytes are an important component in terms of the diversity and functioning of montane forests known as biodiversity hotspots. Bryophytes are highly dependent on their external environments because they are sensitive to environmental changes related to disturbance, fragmentation, air pollution, and climate change. The richness and composition of bryophytes in remnants of primary and secondary forests were analyzed, where the richness and cover were recorded on trunk bases of 120 trees. Changes in species richness and diversity were analyzed using generalized linear models (GLMs), and changes in species composition, using multivariate analysis. A total of 57 bryophyte species (36 liverworts and 21 mosses) were recorded in trunk bases. For the first time, 19 new liverworts for the province of El Oro are reported. The richness and diversity of bryophyte species decrease in disturbed forests when compared to primary forests, with a marked decrease in species less adapted to conditions of high light (shade epiphytes). In the same line, species composition is different in each type of forest, where bryophytes with high humidity requirements were abundant in primary forests. This study confirms that forest disturbance is a key factor in determining not only the number of species but also the composition of bryophyte species. The maximum tree diameter and primary forest remnants are important factors in the conservation of sensitive bryophyte species at the base of trees in one of the last remnants of mountain forests in El Oro Province, Ecuador.
Root anatomical traits regulate water transport and resource acquisition in forest ecosystems, yet their variation and coordination with aboveground traits remain poorly understood in tropical forests. We investigated patterns of interspecific variation in four root anatomical traits (vessel diameter, vessel density, vessel lumen fraction, and theoretical hydraulic conductivity) across 20 tree species representing contrasting growth strategies in a premontane tropical forest of southern Ecuador. Using 160 root samples from transport roots (4–8 mm diameter), we quantified anatomical traits through microscopy and calculated theoretical hydraulic conductivity. We analyzed correlations with wood density and leaf functional traits and performed principal component analyses to assess trait coordination. Species exhibited substantial variation in root anatomical traits, ranging from acquisitive strategies with large vessel diameters (67.6 μm in Ocotea sp.) and high hydraulic conductivity (73.9 kg m−1 MPa−1 s−1 in Alchornea glandulosa) to conservative strategies with high vessel density (>185 vessels/mm2 in Leonia crassa and Aspidosperma rigidum). However, 60% of species displayed intermediate trait values, suggesting compensatory strategies rather than extreme specialization. We documented strong negative correlations between vessel diameter and both vessel density (r = −0.74) and wood density (r = −0.51), pointing at hydraulic efficiency-safety trade-offs. Principal component analysis revealed that leaf traits operated orthogonally to root anatomical traits, indicating independent axes of functional variation rather than coordinated whole-plant strategies. These decoupling challenges traditional plant economics spectrum assumptions and evidence that plants optimize above- and belowground functions through independent evolutionary pathways. Our findings highlight the prevalence of intermediate hydraulic strategies in tropical tree communities and provide new insights into the functional organization of diverse forest ecosystems.