Vertical stratification of epiphytic bryophytes found on Quercus humboldtii (Fagaceae) from Boyacá, Colombia. Oak forest represents an ecologically important plant formation in Colombia, partly due to the large amount of epiphyte flora that harbors, especially non-vascular plants which have been poorly studied in Colombia. One of the biggest oak forests in the country is the one found in the Parque Natural Municipal "Robledales de Tipacoque" (PNMRT), in Boyacá, municipality of Tipacoque. The epiphyte bryoflora was evaluated in Q. humboldtii, using canopy climbing techniques and dividing the trees (25 individuals sampled) each into five layers (base, trunk, inner canopy, middle and outer canopy). A total of 365 samples were collected: 29% liveworts and 71% mosses. Hepatics represented 10 families, 16 genera and 26 species; mosses 11 families, 26 genera and 49 species. Considering the tree layers, the most diverse one was the base with 51 species, followed by the trunk with 43; in the canopy, the inner canopy was found the most diverse with 28 species, and was followed by the middle canopy with 18, and the outer canopy with 15. A species similarity index shows that the trunk and the middle canopy were the most closely related (0.42) in terms of species composition. The results showed that non-vascular plants were mostly found in lower layers (base and trunk), where the diversity was greater, richer (species number), and this might be caused by the microclimatic conditions in these places, such as higher humidity, lower light intensity and shade. Thus, some species are considered shade epiphytes (ombrophiles) because they are unique to these areas, like Bazzania gracilis and Taxilejeunea pterigonia, among others. Likewise, Jungermannia sp. is considered a sun epiphyte (heliophilous) because it is found only in the outer canopy. We concluded that Q. humboldtii could be considered as a potential host for the conservation of non-vascular epiphytes in Colombian forests. Rev. Biol. Trop. 62 (2): 719-727. Epub 2014 June 01.

Presentado el 6 de noviembre de 2013, aceptado el 4 de febrero de 2014, fecha de reenvío el 17 de febrero de 2014.Citation / Citar este artículo como: SIMIJACA-SALCEDO DF, VARGAS-ROJAS DL, MORALES-PUENTES ME. Uso de organismos vegetales no vasculares como indicadores de contaminación atmosférica urbana (Tunja, Boyacá, Colombia). Acta biol. Colomb. 2014;9(2):221-232. RESUMENLos líquenes y briófitos son organismos útiles en la determinación de la calidad del aire. En la ciudad de Tunja (departamento de Boyacá, Colombia), es evidente la escasez de zonas verdes por el aumento en las construcciones, lo que contribuye al detrimento de la pureza atmosférica y trae consigo el deterioro de la salud de la ciudadanía y la reducción de los hábitats y poblaciones de las plantas criptógamas. Mediante la determinación del Índice de Pureza Atmosférica (IPA) se identificaron las zonas con mayor influencia de contaminantes del aire. Parmotrema austrosinense corresponde a la especie más frecuencia; y la estación de la Normal Femenina, con IPA de 52,2196 es influenciada por los contaminantes atmosféricos; las estaciones de los Parques Santander y Semáforos son las más contaminadas (IPA 8,5333) con solo dos especies (Heterodermia albicans y Lobariaceae sp.). Se destaca la evaluación en la Reserva Forestal Protectora El Malmo con un IPA de 34,0281 y 23 especies. Los valores de IPA se agruparon en zonas de isocontaminación para ser representados cartográficamente. El uso de organismos bioindicadores es una estrategia natural y económica que permite zonificar las urbes y enfocar planes para revegetalización de ciudades, generando la disminución del impacto de contaminantes en el aire con el fin de mejorar la calidad de vida de los pobladores.Palabras clave: briófitos, contaminación, índice, líquenes, urbano. ABSTRACTLichens and bryophytes are useful organisms in air quality determination. In the city of Tunja (Boyacá, Colombia), is evident the lack of green areas by the increase of building, which contributes to the detriment of the atmospheric purity making unhealthy conditions to the citizens and habitats and population reduction of cryptogamic plants. Using the Index of Atmospheric Purity (IAP) we identified the greater influence air pollutants areas. Parmotrema austrosinense has the highest frequency; and the Normal Femenina station with an IAP of 52,2196 is an atmospheric pollutants influenced area; Parque

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Background and Aims: The high Andean forest in Colombia corresponds to a plant community located between 2400-3200(-3500) m a.s.l., characterized by the presence of arboreal species with restricted distributions that determine their physiognomy and composition. Nevertheless, these species have been affected by agricultural activity that has generated a loss of connectivity and richness. This research records the species richness, composition, and distributional data for the vascular flora in the high Andean forest of the Bijagual Massif, Bocayá, Colombia. Methods: Sampling was carried out in 27 transects. The specimens were organized under the APG IV classification system, curated and deposited in the UPTC herbarium (Universidad Pedagógica y Tecnológica de Colombia). The number of species, list of taxa, distributions for Colombia, and conservation categories according to the IUCN were noted. Results: We registered 327 species distributed in 151 genera and 69 families; 187 species (56%) were native to the Andean region, 51 (15%) were endemic to the Andes and 24 (7%) were endemic to the Eastern cordillera of the Andes, Colombia. Schefflera bejucosa is a new distributional record for Boyacá. Greigia stenolepis, Hieronyma rufa, Puya goudotiana and Tillandsia pallescens are Near Threatened (NT). Plutarchia guascensis, Quercus humboldtii and Symplocos venulosa are classified as Vulnerable (VU), and Diplostephium oblongifolium and Dunalia trianaei as Endangered (EN). Conclusions: Bijagual is a biological corridor with great potential for biodiversity compared to other high Andean areas in Colombia. Species richness is influenced by other localities near the Massif (Tota and Mampacha), in addition to a possible stochastic and heterogeneous distribution between sampling units. Miconia, Pentacalia, Epidendrum, Elaphoglossum, Tillandsia, and some other genera are species-rich. Clusia alata, Weinmannia balbisiana, Weinmannia rollottii, Ternstroemia cf. camelliifolia, and Brunellia comocladifolia define the arboreal and shrub physiognomy of Bijagual.

Se elaboró un catálogo de las angiospermas del páramo de Bijagual con información de las especies, distribución local y nacional. Se registraron 35 familias, 73 géneros y 120 especies.