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An inventory of 384 plots on 64 trees, in four localities across the Colombian Amazon region (Amazonas, Caquetá, Putumayo, Vaupés), yielded 160 species of epiphytic bryophytes (116 of liverworts, 44 of mosses), in 64 genera and 26 families. Sampling was carried out in four non-seasonally flooded forests (Terra Firme), where bryophytes where collected from the base to the outer canopy, of 16 trees per locality. The flora is characterized by dominance of liverworts, especially Lejeuneaceae. The families with the highest number of records were Lejeuneaceae (55%), Calymperaceae (10%), Lepidoziaceae (8%), Octoblepharaceae (6%) and Sematophyllaceae (5%). The most common genera in number of records were Cheilolejeunea (11%), Pycnolejeunea (8%), Archilejeunea (8%) Ceratolejeunea (8%) and Syrrhopodon (7%). Syrropodon and Lejeunea were the most species-rich genera, followed by Ceratolejeunea and Cheilolejeunea. In average, the localities had 102 species in sixteen phorophytes. In terms of species richness and composition there were no significant differences between the four localities.

O objetivo deste estudo foi avaliar a resistência de união entre uma cerâmica sintética de fluorapatita e leucita livre de feldspato e um cimento resinoso dual, variando o tempo de condicionamento ácido da superfície da cerâmica. Foram confeccionados 16 blocos de cerâmica (IPS d. SIGN- Ivoclar-Vivadent) que foram divididos aleatoriamente em 2 grupos (n=8), conforme o tempo de condicionamento ácido da superfície cerâmica: G1 - condicionamento durante 30 segundos com ácido fluorídrico 10%, seguido da aplicação do agente silano (Primer ceramic, 3M/Espe); G2: condicionamento com ácido fluorídrico 10% durante 2 minutos, seguido da aplicação do silano (Primer ceramic, 3M/Espe). Os blocos de cerâmica foram unidos a blocos de resina composta, recém confeccionados, (Fill Magic, Vigodent) com o cimento resinoso Rely X (3M/Espe) sob uma carga de 750g. Os conjuntos foram armazenados em água por 24h e seccionados em dois eixos, x e y, obtendo-se corpos-de-prova (CP) com área de aproximadamente 0,7 mm2. Os CP foram submetidos ao ensaio de microtração a uma velocidade de 0,5 mm/min. Os resultados foram submetidos a duas análises estatísticas utilizando todos os CP, incluindo os com valores zero (G1 = 12,99 ± 6,7 MPa e G2 = 14,97 ± 3,7 MPa) e excluindo os com valores zero (G1 = 20,19 ± 3,8 MPa e G2 = 22,31 ± 2,8 MPa). Não foi observada diferença estatística entre os grupos em nenhuma das análises (p>0,05).

Vitalianthus was established by Schuster & Giancotti (1993) based on Drepanolejeunea bischleriana K.C.Pôrto & Grolle (1987: 301), which is endemic to the Atlantic coast of north-eastern Brazil. This genus is related to Drepanolejeunea (Spruce 1884: 76) Schiffner (1893: 119) (Gradstein et al. 2001, Gradstein & Costa 2003, He et al. 2012a, b) and characterized by the 1) hyaline papilla at the proximal side of lobule tooth, 2) unbroken basal vitta of 3-7 ocelli in leaf lobes, 3) bilobed underleaves with upright lobes, 4) gynoecial innovations with a pycnolejeuneoid leaf sequence, 5) perianth keels unarmed, and 6) absence of specialized cladia (He et al. 2012a). In addition to the type species, this genus currently also contains Vitalianthus urubuensis Zartman & Ackerman (2002: 267) from the Amazonian rainforests of Brazil and Colombia (Zartman & Ackerman 2002, Mota de Oliveira & ter Steege 2013, Campos et al. in prep.), and V. guangxianus Zhu et al. (2012a: 32). Our examination of type material and recent collections of Vitalianthus urubuensis from Brazil and Colombia reveals that the hyaline papilla of the leaf lobule is distal as in Cheilolejeunea (Spruce 1884: 79) Schiffner (1893: 118) (Fig. 1E,F). The moniliate, unbroken vitta of ocelli in the leaf lobes, one of the most important features of Vitalianthus, also occurs in some species of Cheilolejeunea, e.g. in Cheilolejeunea falsinervis (Sande Lacoste 1854: 321) Schuster & Kachroo (1961: 56) from Asia and Australasia. It thus appears that V. urubuensis is morphologically more similar to Cheilolejeunea than to Vitalianthus. The morphological affinity between Vitalianthus urubuensis and Cheilolejeunea is confirmed by our unpublished molecular data (ITS, trnG and trnL-F; Wei et al., in prep.) which show that V. urubuensis and several species of Cheilolejeunea form a monophyletic lineage. Therefore, the following new combination is necessary.

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We studied the community structure and diversity of epiphytic bryophytes in a vertical gradient from tree base to canopy in four lowland rain forest sites of the Colombian Amazon (Amazonas, Caquetá, Putumayo, and Vaupés). Each of the 64 sampled phorophytes was divided into six height zones from the base (Z1) to the outer canopy (Z6). As a subproject, we carried out a genetic population study using the liverwort Cheilolejeunea rigidula (Lejeuneaceae) as our model species, which occurred in all six height zones. In addition to 65 successfully sequenced samples from the study sites, we included individuals of C. rigidula from Guiana and Brazil (Manaus and Tapajos) to investigate the connectivity and genetic structure of this species across the Amazon region and to evaluate the genetic structure based on phorophyte height zones. Each site in Colombia, Brazil and Guiana was considered a subpopulation. The sequenced chloroplast markers (partial atpB gene, partial psbA gene/psbA-trnH spacer) showed little variation across the Amazon and the height zones on the trees. The nuclear marker (ITS) showed a spatial structure indicating genetic differentiation of subpopulations across the Amazon, but little genetic differentiation of C. rigidula along the height of the trees. The gradient across the Amazon shows a relationship between genetic distance and geographic distance, indicating dispersal limitations (P<0.001). At local and regional scales, our results suggest that dispersal can have a dominant effect on populations and communities, increasing connectivity.