Floristic composition and community structure of epiphytic angiosperms in a terra firme forest in central Amazonia

This survey aimed to describe the floristic composition and structure of the epiphytic community occurring in a terra firme forest in the city of Coari, Brazil, in the Amazon region. Data collection was performed with a 1.5 ha plot method, with which upland, slope and lowland habitats were sampled. All angiosperm epiphytes and their host plants (diameter at breast height > 10 cm) were sampled. We recorded 3.528 individuals in 13 families, 48 genera and 164 species. Araceae was the most prevalent family with regard to the importance value and stood out in all related parameters, followed by Bromeliaceae, Cyclanthaceae and Orchidaceae. The species with the highest epiphytic importance values were Guzmania lingulata (L.) Mez. and Philodendron linnaei Kunth. The predominant life form was hemiepiphytic. Estimated floristic diversity was 3.2 (H'). The studied epiphytic community was distributed among 727 host plants belonging to 40 families, 123 genera and 324 species. One individual of Guarea convergens T.D. Penn. was the host with the highest richness and abundance of epiphytes. Stems/trunks of host plants were the most colonized segments, and the most favorable habitat for epiphytism was the lowlands, where 84.1% of species and 48.2% of epiphytic specimens were observed

Species richness and abundance of epiphytic Araceae on adjacent floodplain and upland forest in Amazonian Ecuador

Abstract. Terrestrial plant communities of adjacent upland and floodplain forest of the Amazonian lowland differ from each other in species richness and composition. Epiphytes are generally not considered as being affected by flooding, but we found considerable variation in the communities of epiphytic Araceae of flooded and unflooded forest. Contrary to findings from tree or ground herb communities, no depletion in overall species richness was observed among epiphytic aroids of the floodplains. Abundance and number of epiphytic aroid species per phorophyte were significantly higher than in upland forest, and the species composition varied conspicuously between the two forest types. We suggest that these differences are due to elevated humidity and better soil quality on the floodplains and reject the assumption that flooding has no effect on the epiphytic community

A new species of Anthurium (Araceae) from southern Ecuador and a revision of the Anthurium oxybelium Schott complex

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Deletion of endothelial TGF-β signaling leads to choroidal neovascularization.

The molecular pathogenesis of choroidal neovascularization (CNV), an angiogenic process that critically contributes to vision loss in age-related macular degeneration (AMD) is unclear. Here we analyzed the role of transforming growth factor (TGF)-β signaling for CNV formation by generating a series of mutant mouse models with induced conditional deletion of TGF-β signaling in the entire eye, the retinal pigment epithelium (RPE) or the vascular endothelium. Deletion of TGF-β signaling in the eye caused CNV, irrespectively if it was ablated in newborn or three-week-old mice. Areas of CNV showed photoreceptor degeneration, multilayered RPE, basal lamina deposits and accumulations of monocytes/macrophages. The changes progressed leading to marked structural and functional alterations of the retina. While the specific deletion of TGF-β signaling in the RPE caused no obvious changes, specific deletion in vascular endothelial cells caused CNV and a phenotype quite similar to that observed after the deletion in the entire eye. We conclude that impairment of TGF-β signaling in the vascular endothelium of the eye is sufficient to trigger CNV formation. Our findings highlight the importance of TGF-β signaling as key player in the development of ocular neovascularization and indicate a fundamental role of TGF-β signaling in the pathogenesis of AMD