Browsing by Author "Hepp, Josefina"

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    Characterisation of seed dormancy of 12 Chilean species of Nolana (Solanaceae) from the coastal Atacama Desert
    (CAMBRIDGE UNIV PRESS, 2021) Hepp, Josefina; Gomez, Miguel; Leon Lobos, Pedro; Montenegro, Gloria; Vilalobos, Luis; Contreras, Samuel
    The genus Nolana (Solanaceae) comprises numerous species endemic to the coastal Atacama Desert of Chile and Peru of high ornamental potential and conservation value. The environments in which these species have evolved and are present today correspond to particular conditions in the midst of a hyper-arid habitat, so the study of their germination requirements and characterisation of seed dormancy becomes important in terms of conservation but also for ecological and evolutionary purposes. Different treatments were performed on mericarps of 12 species of Nolana: control (intact seeds imbibed in distilled water), scarification in funicular plug and distilled water and scarification in funicular plug and addition of GA(3) (500 ppm); their permeability to water was also tested. It was determined that the species did not present physical dormancy, as had been previously reported, but rather physiological dormancy (PD). Germination results after treatments were not homogeneous among all 12 species, indicating differences in their dormancy levels. Also, the important role of the endosperm in the prevention of germination for the studied Nolana species was highlighted. Regarding the relationship between the level of PD (expressed as the percentage of germination for the most successful treatment) and the latitudinal distribution of the species or their phylogenetic closeness, it was determined that, for the studied species, their proximity in terms of clades was more relevant than their latitudinal distribution.
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    Characterization of seed dormancy of Nolana (Solanaceae) in the coastal Atacama Desert of Chile.
    (2019) Hepp, Josefina; Contreras E., Samuel; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
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    Effects on the flora and vegetation of the extreme precipitation event of August 2015 in Alto Patache, Atacama Desert, Chile
    (PONTIFICA UNIV CATOLICA CHILE, INST GEOGRAFIA, 2017) Pliscoff, Patricio; Zanetta, Nicolas; Hepp, Josefina; Machuca, Javiera
    During the extreme precipitation event related with "El Nino", which occurred in August 2015 on the coast of the Tarapaca region, Atacama Desert, rainfall of 50 mm was recorded at the Alto Patache Fog Oasis (annual average of 1 mm), activating germination of many species present on the site. After the event, transects were demarcated and the presence and dominance of vegetation was recorded. The floristic data identified was compared with historical records and related with the distribution of fog, measured between the years 2001 and 2002. Results show 42 species identified, 78% of all known plants in the area, with one new record (Tiquilia sp.). The floristic analysis allowed the identification of three vegetation units, and a greater diversity of species was observed in lower areas of the coastal mountain chain.
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    Seed dormancy of Nolana jaffuelii I.M.Johnst. (Solanaceae) in the coastal Atacama Desert
    (2015) Cabrera, Elisa; Hepp, Josefina; Gómez, Miguel; Contreras E., Samuel