Abstract. Structure of the high Andean forest and paramo in the Bijagual Massif, Boyacá, Colombia. Introduction: Colombia has increased research due to the necessity of knowing the country´s biodiversity and ecosystems, as well as to establish priorities for their protection throughout the national territory. The knowledge of the Boyacá ecosystems and the high Andes are not an exception. Objective: this work provides information on diversity and structure of the Bijagual Massif, a high mountain area defined as a biological corridor, with paramo (2 900 - 3 460 masl) and high Andean forest (2 682 -3 268 masl) ecosystems. Methods: Sampling consisted of 27 random transects in the high Andean forest (100 x 2.5 m) and 13 in the paramo (10 x 5 m). We recorded abundance data, growth form, height, coverage, DAP and basal area. We calculated diversity analyses (H’, D and Jaccard), of vertical and horizontal structure. Results: Estimated species richness of 429 species in 86 families. Similarity does not exceed 46 % between sampling units, data that supports the heterogeneity of the Bijagual Massif. We recorded 10 777 individuals in the forest. The most abundant and richest growth forms were herbs (2 595/104) and trees (2 189/67), while lower in abundance and richness were vines (466/29). In the paramo 3 337 individuals, with a dominance of herbs (in frailejonal, shrubs and pajonal), rosettes (in frailejonal and pajonal) and shrubs. Species with ecological representativeness are: Clusia multiflora, C. elliptica, C. alata, Weinmannia rollottii, Brunellia comocladifolia and Viburnum triphyllum. Conclusion: These results confirm the uniqueness of these high mountain ecosystems and the need to maintain the heterogeneity before the occurence of soil transformation processes. The last, is supported by the high species turnover among sampling units, the dominance per physiognomic type, and the ecological significance of arboreal and shrub species in the forest and those that reoccur in the paramo. Here we define Bijagual, as a biological corridor with great biodiversity.

In high mountain ecosystems, Hepaticae is prominent and are essential to regulate and maintain hydrological cycles; they also contribute to nutrient recycling. We sampled five different substrates (decomposing matter, tree base, bare soil, rocks and flush root) of the "Robledales de Tipacoque" Natural Park and recorded 52 species of Hepaticae belonging to 21 genera and 12 families. The families having the highest number of species were the Plagiochilaceae with 22 (40.7%) and Lejeuneaceae with nine (16.6%), and the substrates with the highest number of species were decaying matter (30), followed by rock (22). The floristic composition in altitudinal belts is so distinct, that species of Hepaticae were found constrained to one altitudinal range.

Se amplía la lista de especies de Melastomataceae del departamento del Chocó, con ocho taxones del género Blakea (Melastomataceae) (B. andreana, B. cuatrecasii, B. megaphylla, B. pilosa, B. stipulacea y B. vallensis), así como el redescubrimiento de B. paleacea y B. platypoda; se dan a conocer detalles de las características de flores, frutos y semillas de dichos taxones. Se presentan las descripciones ampliadas de las especies, así como datos sobre distribución, clave taxonómica, fotografías, información del hábitat y fenología.

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